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GOVERNMENT ENGINEERING COLLEGE, VALSAD MECHANICAL ENGINEERING DEPARTMENT

CERTIFICATE

This is to certify that Mr./Miss______of

Mechanical Branch, Sem-VII, Enrollment No.______, has satisfactorily completed his/her term work for the Internal Combustion Engine

(2161902) during odd term-20____.

Date :

Sign of Faculty Head of the Department

GOVERNMENT ENGINEERING COLLEGE, VALSAD MECHANICAL ENGINEERING DEPARTMENT

INDEX

Subject: Internal Combustion Engine (2161902)

PRACTICAL SIGN OF TITLE GRADE DATE NO. FACULTY

TO DETERMINE VALVE TIMINGS OF FOUR STROKES PETROL / & PORT 1 TIMING OF TWO STROKES PETROL/DIESEL ENGINE.

TO STUDY ABOUT OF I.C. 2 ENGINE.

TO STUDY ABOUT SUPERCHARGING AND TURBO 3 CHARGING OF I.C.ENGINE.

TO STUDY EXPERIMENTAL PRODUCER & DATA 4 CALCUTION FOR THE ENGINE. TO STUDY ABOUT ENGINE EMISSIONS AND THEIR 5 CONTROL.

TO DETERMINE THE PERFORMANCE OF SINGLE 6 , FOUR , DIESEL ENGINE.

TO DETERMINE THE PERFORMANCE OF FOUR 7 CYLINDER, FOUR STROKE, . TO PERFORM MORSE TEST OF FOUR CYLINDERS, 8 FOUR STROKES, PETROL ENGINE WITH ELECTRICAL DYNAMOMETER. TO PERFORM WILLAN’S LINE METHOD FOR 9 DIESEL ENGINE.

TO STUDY SUPPLY SYSTEM OF ENGINES. 10

GOVERNMENT ENGINEERING COLLEGE, VALSAD MECHANICAL ENGINEERING DEPARTMENT

PRACTICAL 1: TO DETERMINE VALVE TIMINGS OF FOUR STROKES PETROL /DIESEL ENGINE & PORT TIMING OF TWO STROKES PETROL/DIESEL ENGINE. INTERNAL COMBUSTION ENGINE (2161902) B.E. SEM –6th OBJECTIVES:  To understand the basic functional relation between and timing.  To understand and port timing of engine.  To determine valve timing diagram of four stroke engine and port timing diagram of two stroke.

THEORY:

INTRODUCTION Theoretically the inlet valve is opened during the suction stroke and the exhaust valve during the exhaust stroke. In actual practice the valves do not open and close exactly when the at dead centre position. The inlet valve opens a little before the end of exhaust stroke and continues to the initial part of compression stroke. Similarly the exhaust valve opens a little before the end of expansion process and continues to the initial part of suction stroke. There is a small duration of time when both the suction and exhaust are open simultaneously.

PROCEDURE:- To determine the correct direction of rotation of the engine, is turn by hand in either direction and by observing the ; the direction which gives the proper sequence of operations (four strokes) is found out. The next thing is to find cut the position of flywheel, against a pointer fixed near it when the piston is a dead centre position as the crank is perfectly horizontal. Keeping the crank inclined to horizontal by a small angle a chalk mark is made on the piston against the cylinder liner as well as on the flywheel periphery against the pointer. The engine is turned in correct direction of rotation so that after passing through the dead centre position the piston is brought to its original position and a mark is made on the flywheel, against the pointer. It can be seen that the mode point mark is made on the flywheel gives the required position of the piston at outer dead centre (I.D.C). Then for finding out the opening and closing of inlet valve the engine is turned round slowly. When the roller connected to the suction valve just comes in contact with the cam, a mark is made on the flywheel against the pointer. This point gives the position for the beginning of opening of the inlet valve. The flywheel is further rotated and a mark is made on it, when the cam just leaves contact with the roller, indicating closing of the inlet valve.

INTERNAL COMBUSTION ENGINE Prepared By- Dr. Manish K. Mistry

For finding out the opening and closing of the exhaust valve, the same procedure is followed, this time by observing the exhaust valve roller. To determine the time, the injector is removed from the cylinder, turning the flywheel by hand, the moment, the fuel is seen issuing out of injector, and a mark is made on the flywheel. The circumferential distances of those marks from the corresponding dead center position marked on the crank are calculated and the valve timing diagram is drawn.

Valve timing diagram of 4- stroke single cylinder diesel engine IVO - 250 before TDC IVC - 300 after BDC EVO - 450 before BDC EVC - 150 after TDC FVO - 150 before TDC FVC - 250 after TD

Valve timing diagram of 4- stroke single cylinder petrol engine.(low speed) IVO - 100 before TDC IVC - 200 after BDC EVO - 250 before BDC EVC - 50 after TDC

Valve timing diagram of 4- stroke single cylinder petrol engine.(high speed) IVO - 100 before TDC IVC - 500 after BDC EVO - 450 before BDC EVC - 200 after TDC

Port timing diagram of 4- stroke single cylinder petrol engine EPO - 450 before TDC EPC - 450 after BDC TPO - 350 before BDC TPC - 350 after TDC

INTERNAL COMBUSTION ENGINE Prepared By- Dr. Manish K. Mistry

GOVERNMENT ENGINEERING COLLEGE, VALSAD MECHANICAL ENGINEERING DEPARTMENT

PRACTICAL 2: TO STUDY ABOUT IGNITION SYSTEM OF I C ENGINES. INTERNAL COMBUSTION ENGINE (2161902) B.E. SEM –6th OBJECTIVES:  To understand the basic components of ignition system of petrol engine.  To understand types of ignition system and its features.  To understand working of different types of ignition system.

THEORY:

INTRODUCTION The ignition system carries the critical current to the where the spark carries sufficient energy to increase the temperature of surrounding charge to the ignition point at which combustion becomes self-sustaining. The spark appears at the plug gap in S.I engine just as the piston approaches the TDC of the compression stroke, when the engine is idling. At higher speed or during increased operation of the engine the spark is advanced. To produce the necessary high required to jump a set gap of the spark plug to produce spark in the for the ignition of the combustible charge at the correct time. The ignition systems are classified as follows: 1. Battery - ignition system 2. - ignition system 3. Electronic - ignition system|

1) Battery - ignition system:- The components of battery ignition system area battery, an ignition switch, an with or without an added ballast resistor, a which houses the points, the cam , the condenser, the and the advanced mechanism, a spark plug, and low & high tension wirings. There are two circuits of the ignition system; (1) The Primary Circuit and (2) The Secondary circuit. The primary circuit consists of the battery, the ignition switch, the ballast resistor, the primary coil winding, the condenser and the breaker point. The secondary circuit consists of the secondary coil winding, the distributor and the spark plug.

Battery Electronic energy is provided by the storage battery. The six plate – 12 volt battery supplies a steady current for ignition, motor, lighting, and other electric circuits, and provides a reserve of

INTERNAL COMBUSTION ENGINE Prepared By- Dr. Manish K. Mistry

electricity when the current consumed by the electronic equipment exceeds that being produced by the .

Ignition switch: The ignition switch is placed between the battery and the primary winding of the ignition coil. It has extra set of contacts that are used when the switch is turned past ON to START.

Ballast resistor: It may be placed in a series with the primary winding of the ignition coil to regulate the primary current. At low engine speed the average current is high due to longer closer of the contact break point. It is heated up and produces more resistance with cuts down the current. Ignition coil: It is used to step up 12-volts battery to a very high voltage of 10,000 to 20,000 volts to induce an electric spark across the electrodes of the spark plug. The typical ignition coil of metal clad type consists of a primary winding of 200 to 300 turns of thick wire to provide resistance of about 1.5Ώ and the secondary winding is made of a large no of turns about 21,000 of fine enameled wire sufficiently insulated to with stand high . These winding are wound upon a cylindrical soft core, and enclosed by a soft iron shell. The secondary coil is closed to the core and the primary winding is located at outside of the secondary coil. Contact breaker points: It is a mechanical device for making and breaking the primary circuit of the ignition system. it consist of a fixed metal point which is ground and another metal point attached to a movable, spring loaded insulated breaker arm. The metal used is invariably one of the hardest metals, usually tungsten and each point has a circular face of about 3mm diameter. Condenser: As the contact breaker points open, the current from the battery through the primary winding of the coil is stopped. The magnetic field is therefore collapse. The collapsing magnetic field induced current which continuous to flow in the same direction in the primary circuit and thus charges the condenser plate. This absorbs current surges back out of the condenser and towards the ignition coil, thus helping to bring about the complete collapse of the magnetic field in the coil which in turn induces a high voltage of necessary magnitude in the secondary winding. Distributor: It consist of a housing a drive shaft with breaker cam, an advance mechanism, a breaker plate with contact points and a condenser, a rotor, and a cap. The shaft is driven by the of the engine through spiral . It rotates at one-half of the speed of crank shaft. This shaft is usually coupled to another shaft which drives the oil of lubrication. The distributor has several functions; it closes and opens the contact points to complete and interrupt the primary circuit between the battery and the ignition coil. When the primary circuit is completed through the closed contact points, the current flows in the ignition coil and builds up a magnetic field. When the points open by the cam rotation, the primary INTERNAL COMBUSTION ENGINE Prepared By- Dr. Manish K. Mistry

circuit will opened and the current stops flowing. The magnetic field collapses and this produces a high voltage in the secondary winding of the ignition coil.

2) Magneto ignition system: The Magneto ignition system is extensively used in mopeds, three wheelers, motor cycles, sports and racing and reciprocating air craft engines. It is similar to the battery ignition system in the principle except that the magnetic field in the core of the primary and secondary winding is produced by a rotating permanent . The magneto has got its own current generating unit without making the use of battery and ignition coil. It consists of a fixed having primary and secondary winding and a rotating assembly of driven from the engine. It is called high tension magneto. A magneto having no separate secondary winding on its armature is called a low tension magneto. For the spark to occur, the required voltage is produced on stepping up the low tension supply by means of an ignition coil. This system is cheap, reliable and requires little maintenance. The starting of engine is difficult as the magneto does furnish enough voltage for ignition at low speeds. The efficiency of the system improves with the increasing speed.

Advantages: 1) Less maintenance 2) Light in weight and occupies less space 3) Provides high intensity spark at high speeds 4) System is reliable

Disadvantages: 1) Since wirings carry high voltage current, there is a strong possibility of leakage which may cause misfiring of engine 2) The system requires extensive shielding to prevent leakage of high voltage current 3) At low speeds it develops poor quality of spark at the spark of starting

Comparison between battery and magneto ignition system: Battery ignition system (1) It provides high intensity spark at low speeds and low intensity spark at high speed of Engine (2) It needs excessive maintenance of battery system (3) System is less reliable compared to magneto system (4) Cost of system is low (5) System is heavier due to battery weight (6) Variation of can be achieved easily without affecting the spark intensity (7) It occupies more space

INTERNAL COMBUSTION ENGINE Prepared By- Dr. Manish K. Mistry

Magneto ignition (1) It provides low intensity spark at low speeds and high intensity spark at high speeds (2) It does not need maintenance since the battery is eliminated (3) System is more reliable compared to Battery- coil system (4) Cost of system is high (5) System is lighter in weight (6) Variation of ignition timing cannot be achieved easily without affecting the spark intensity (7) It occupies less space

3). Electronic ignition system: (1) Transistorized coil ignition system (TCI)

Transistorized coil ignition system (TCI): This system has been found to offer decided advantages in handling the increasing voltage required for high performance of the engines, longer spark plug life, reduced wear, maintenance of the ignition system and high reliability

Advantages: 1) Higher ignition voltage and a longer duration of spark 2) Reduced wear of C.B. points 3) Consistency of spark voltage over the entire speed range 4) Increased dwell and less contact bounce

Disadvantages: 1) System requires contact breaker points of the conventional system for timing the spark 2) The maximum speed of engine is governed by the limitation of contact breaker mechanism 2) Capacity discharge ignition system (CDI):

A battery of 6 volt usually connected to a transistorized DC to DC converter which is designed to give high voltage in the range of 250-300 V from battery

Advantages:

1) Avoids contact break points and their frequent maintenance 2) Gives better cold starting since the system draws high current at low speed and low current at high speed 3) It provides constant voltage to spark plug at all speeds INTERNAL COMBUSTION ENGINE Prepared By- Dr. Manish K. Mistry

4) Improves the efficiency of the engine

Spark plug:

Its function is to receive high voltage ignition current from secondary coil of ignition system and to supply spark to combustion chamber of engine cylinder which jumps across the electrodes, it consists of a central porceline insulator through which an electrode passes. It has external contact at the top to wire from ignition coil

Types of spark plug:

Spark plugs are classified as hot spark plug and cold spark plug. The operating temperature of the plug depends upon the area of insulation and electrode exposed to the hot gases and the length of the path from electrode points and insulation back to the cooled parts of the cylinder wall in to which the plug is screwed. The plug with a short center electrode is known as cold plug and the plug with the long centre electrode is known as hot plug. Factors affecting spark advance:

1) Mixture strength: for weaker mixture the rate of flame propagation is lower, so the complete combustion period will be greater. In order to obtain the maximum power from weak mixture the spark should therefore be advanced. 2) : with the increase in compression ratio the charge density will be increased, which will increase the rate of propagation. The spark advance must therefore be reduced as the compression ratio is increased. 3) Engine speed: as the engine speed increases the combustion duration in terms of degrees crank-angle also increases. Therefore the angle of spark advanced must increase as the speed increases. 4) Turbulence: as the degree of turbulence is increased, more quality of mixture passes the ignition point in a certain time, so the effect is similar to that of increased flame speed. Increasing the turbulence should therefore require a retardation of the ignition timing. 5) Engine load: at light loads a partial vacuum is generated in the manifold, resulting in less quantity of mixture during the compression stroke. There is a large gain in efficiency at light loads by advancing the ignition timing. 6) Types of : a fuel having lower flame speed will need a greater spark advance for maximum power and economy.

Spark advance mechanism:

INTERNAL COMBUSTION ENGINE Prepared By- Dr. Manish K. Mistry

When engine is idling the spark is timed to occur just before the piston reaches the TDC on the compression stroke. At higher speeds it is necessary to deliver the spark to the combustion chamber earlier. This gives ample time for mixture to burn and deliver its power to the piston

There are two types

1) Centrifugal advanced mechanism 2) Vacuum advance mechanism

Centrifugal advance mechanism: It consists of advance cam integral with the ignition cam, a pair of governors or advance weights and a plate attached to the distributor shaft. All are located beneath the ignition cam and breaker plate. As the engine speed increases the advance weights are thrown out against spring tension. They are pivoted on their pins. As they swing out they push the advance cam so that it rotates the breaker cam ahead of the distributor shaft. This advance cause the cam open. The timing of spark to the cylinder thus varies at high speeds. This advance timing is as much as 28 degrees of crank angle.

Vacuum advance mechanism: The vacuum advance is obtained by attaching the movable breaker plate to a diaphragm which is held in full retard position by a spring. The breaker point is supported in bearings so that it can turn with respect to distributor housing. The spring loaded side of a diaphragm is connected through a vacuum line to the intake manifold through the . There is no vacuum advance in the idling position. As the throttle valve opens it swings past the opening of vacuum passage the intake manifold the vacuum can then draw air from the vacuum line and the air tight chamber in the vacuum advance mechanism. This cause the diaphragm to move against the spring. The linkage of the breaker plate then rotates the breaker plate. This movement carries the contact points around so the cam, as it rotates, closes and opens the points earlier in the cycle and supplies spark at the spark plug earlier at the compression stroke.

REVIEWS QUESTIONS 1. Draw the basic lay out of (1) Battery - ignition system (2) Magneto - ignition system (3) Electronic - ignition system 2. List three moped/scooter and two ignition system and write detail specifications of each.

INTERNAL COMBUSTION ENGINE Prepared By- Dr. Manish K. Mistry

GOVERNMENT ENGINEERING COLLEGE, VALSAD MECHANICAL ENGINEERING DEPARTMENT

PRACTICAL 3: TO STUDY ABOUT SUPERCHARGING AND TURBO CHARGING OF I.C.ENGINE INTERNAL COMBUSTION ENGINE (2161902) B.E. SEM –6th OBJECTIVES:  To understand the basic function of turbocharging and supercharging.  To understand requirement of boosting system.  To understand types of boosting system.

THEORY:

OBJECTIVES OF SUPER CHARGING Supercharging of internal combustion engines has been used for many years as a method to improve engine performance and efficiency. Entering the millennium, a new trend is appearing. The trend points to small displacement engines in order to meet federal emission legislation on fuel consumption and emission control. The driver, however, still demands the same performance they're used to.

A good way to meet these needs is supercharging otherwise known as . The purpose of supercharging an engine is to raise the density of the air charge, before it's delivered to the cylinders. Thus, the increased mass of air trapped and then compressed in each cylinder during each induction and compression stroke makes more available for combustion than the conventional method of drawing the fresh air charge into the cylinder (naturally aspirated). Consequently, more air and fuel per cycle will be forced into the cylinder, and this can be efficiently burnt during the combustion process to raise the engine power output to higher than would otherwise be possible. Generally, there are three basic types of "," the most popular being the driven , mechanically driven superchargers and the pressure wave . The mechanically driven supercharger is broken up into two groups as well, the mechanically driven centrifugal supercharger and the mechanically driven positive displacement supercharger such as the screw type and roots type. In automotive and marine applications, the pressure wave supercharger is rarely used. The turbo and roots type superchargers have been the most popular forced induction methods in the past. While the turbo creates great peak , turbo lag and high emissions due to the thermal mass are severe drawbacks of the turbocharger. Small displacement engines need higher pressure ratios to achieve the performance demanded by the driver. This fact increases the mentioned drawbacks of the turbo and makes the turbocharger a less desirable alternative for supercharging than the mechanical twin screw supercharger. The Whipple twin screw

INTERNAL COMBUSTION ENGINE Prepared By- Dr. Manish K. Mistry

charger does not have the usual drawbacks of earlier mechanical superchargers such as the roots type, such as poor efficiency especially at high pressure ratios, high rpm, high noise level as well as high price. Comparative tests made independently by Whipple Industries, show that the twin screw is the most effective supercharging method available. The purpose of supercharging in diesel engine is to compress the fresh air out of the working cylinder. And then the density of air in cylinder can be increased by increasing the air pressure. So more fuel can be combusted and the power of diesel engine is increased too. Lots of practice indicates that supercharging is the best way to increase the power and economy of diesel engine. So supercharging is widely used recently. The equipment which presses the air or mixed air to definite pressure is called compressor. The pressure of air which has been pressed is called supercharging pressure. And it is signed with Pk. Supercharging system of diesel engine contains compressor, compressor driving equipment and cooler. Supercharging system can be divided into 3 types by the difference of energy source in driving supercharge.

EFFECT OF SUPERCHARGING  Air is supplied at high pressure which increases .  Supercharged engines develop more power Mechanical efficiency is more than that of naturally aspirated engines.  Supercharging gives better turbulence, proper air fuel ratio and efficient combustion of fuel.  The specific fuel consumption of super charged engines is less due to better turbulence and proper air fuel mixture.  Super charging tends to increase the possibility of detonation in SI engines.  Super charging tends to decrease the possibility of knocking in CI engines.  At high altitudes, it is possible to obtain sufficient air by supercharging only.  Super charging shortens the 'delay period'

TURBOCHARGERS: are a type of forced induction system whose function is same as that of Supercharger. They compress the air flowing into the engine. A turbocharged engine produces more power overall than the same engine without the charging. This can significantly improve the power to weight ratio for the engine.

In order to achieve this boost, the turbocharger uses the exhaust flow from the engine to spin a , which in turn spins an air pump. The turbine in the turbocharger spins at speeds of up to 150,000 RPM. The turbocharger is bolted to the of the engine. The exhaust from the cylinders spins the turbine, which works like a engine. The turbine is connected by a shaft to the compressor, which is located between the and the intake manifold. The compressor pressurizes the air going into the . INTERNAL COMBUSTION ENGINE Prepared By- Dr. Manish K. Mistry

The exhaust from the cylinders passes through the turbine blades, causing the turbine to spin. The more exhaust that goes through the blades, the faster they spin. On the other end of the shaft, turbine is attached to the compressor which air into the cylinders. The compressor is a type of centrifugal pump; it draws air in at the centre of its blades and flings it outward as it spins. In order to handle speeds of up to 150,000 rpm, the turbine shaft has to be supported very carefully. Most turbochargers use a ‘Fluid Bearing’. This type of bearing supports the shaft on a thin layer of oil that is constantly pumped around the shaft. This serves two purposes: It cools the shaft and some of the other turbocharger parts and it allows the shaft to spin without much friction. Some turbochargers use ‘Ball Bearings’ instead of fluid bearings to support the turbine shaft. But these are not your regular ball bearings, they are super precise bearings made of advanced materials to handle the speeds and temperatures of the turbocharger. Ceramic turbine blades are lighter than the steel blades used in most turbochargers. When air is compressed, it heats up; and when air heats up, it expands. Some of the pressure increase from a turbocharger is the result of heating the air before it goes into the engine. An or charge air cooler is an additional component that looks something like a radiator, except air passes through the inside as well as the outside of the intercooler. The intake air passes through sealed passage ways inside the cooler, while cooler air from outside is blown across fins by the engine cooling .

LIMITATIONS OF TURBO CHARGING: The use of turbochargers requires special exhaust manifolds. Fuel injection has to be modified to inject more fuel per unit time. The efficiency of the turbine blades is very sensitive to gas velocity so that it is very difficult to obtain good efficiency over a wide range of operations. One of the main problems with turbochargers is that they do not provide an immediate power boost. It takes a second for the turbine to get up to speed before boost is produced. This results in a lag known as ‘Turbo Lag’.

METHODS TO OVERCOME TURBO LAG One way to decrease turbo lag is to reduce the inertia of the rotating parts, mainly by reducing their weight. This allows the turbine and compressor to accelerate quickly, and start providing boost earlier. A small turbocharger will provide boost more quickly and at lower engine speeds. Most automotive turbochargers have a waste gate, which allows the use of a smaller turbocharger to reduce lag. Some engines use two turbochargers of different sizes. The smaller one spins up to speed very quickly, reducing lag, while the bigger one takes over at higher engine speeds to provide more boost.

INTERNAL COMBUSTION ENGINE Prepared By- Dr. Manish K. Mistry

REVIEW QUESTIONS (1) Define Supercharging And Give Its Advantage And Disadvantage. Give Limitation Of Supercharging. (2) Which are the supercharging limitation for SI engine and CI engine? (3) Explain method of supercharging. (4) Write objectives of supercharging. (5) What do you mean by turbo charging? Write advantage and limitation of turbo charging. (6) Which are the types of superchargers? Explain centrifugal type supercharger.

INTERNAL COMBUSTION ENGINE Prepared By- Dr. Manish K. Mistry

GOVERNMENT ENGINEERING COLLEGE, VALSAD MECHANICAL ENGINEERING DEPARTMENT

PRACTICAL 4: TO STUDY EXPERIMENTAL PRODUCER & DATA CALCUTION FOR THE ENGINE. INTERNAL COMBUSTION ENGINE (2161902) B.E. SEM –6th OBJECTIVES:  To understand the basic performance parameters of engines.  To understand standard method to determine various parameters of engine.  To understand different instruments/tools used to determine the different parameters.

THEORY:

TERMINOLOGY Engine Cylinder diameter () (D): The nominal inner diameter of the working cylinder.

Piston area (A): The area of a circle of diameter equal to engine cylinder diameter (bore). A = /4  D2 Engine Stroke length (L): The nominal distance through which a working piston moves between two successive reversals of its direction of motion. Dead center: The position of the working piston and the moving parts, which are mechanically connected to it at the moment when the direction of the piston motion is reversed (at either end point of the stroke). Bottom dead center (BDC): Dead center when the piston is nearest to the . Sometimes it is also called outer dead center (ODC). Top dead center (TDC): Dead center when the position is farthest from the crankshaft. Sometimes it is also called inner dead center (IDC).

Swept volume (VS): The nominal volume generated by the working piston when traveling from one dead center to next one, calculated as the product of piston area and stroke. The capacity described by engine manufacturers in cc is the swept volume of the engine. Vs = A  L = /4  D2L

Clearance volume (VC): The nominal volume of the space on the combustion side of the piston at top dead center.

Cylinder volume: The sum of swept volume and clearance volume. V = VS+VC Compression ratio (CR): The numerical value of the cylinder volume divided by the numerical value of clearance volume. CR = V/Vc

FOUR STROKE CYCLE ENGINE: In four-stroke cycle engine, the cycle of operation is completed in four strokes of the piston or two revolutions of the crankshaft. Each stroke consists of 1800 of crankshaft rotation and hence a cycle

INTERNAL COMBUSTION ENGINE Prepared By- Dr. Manish K. Mistry

consists of 7200 of crankshaft rotation. The series of operation of an ideal four-stroke engine are as follows:

1. Suction or Induction stroke: The inlet valve is open, and the piston travels down the cylinder, drawing in a charge of air. In the case of a spark ignition engine the fuel is usually pre-mixed with the air. 2. Compression stroke: Both valves are closed, and the piston travels up the cylinder. As the piston approaches top dead Centre (TDC), ignition occurs. In the case of compression ignition engines, the fuel is injected towards the end of compression stroke. 3. Expansion or Power or Working stroke: Combustion propagates throughout the charge, raising the pressure and temperature, and forcing the piston down. At the end of the power stroke the exhaust valve opens, and the irreversible expansion of the exhaust gases is termed ‘blow-down’. 4. Exhaust stroke: The exhaust valve remains open, and as the piston travels up the cylinder the remaining gases are expelled. At the end of the exhaust stroke, when the exhaust valve closes some exhaust gas residuals will be left; these will dilute the next charge.

TWO STROKE CYCLE ENGINE. In two stroke engines the cycle is completed in two strokes of piston i.e. one revolution of the crankshaft as against two revolutions of four stroke cycle engine. The two-stroke cycle eliminates the separate induction and exhaust strokes.

1. Compression stroke: The piston travels up the cylinder, so compressing the trapped charge. If the fuel is not pre-mixed, the fuel is injected towards the end of the compression stroke; ignition should again occur before TDC. Simultaneously under side of the piston is drawing in a charge through a spring loaded non-return inlet valve. 2. Power stroke: The burning mixture raises the temperature and pressure in the cylinder, and forces the piston down. The downward motion of the piston also compresses the charge in the . As the piston approaches the end of its stroke the exhaust port is uncovered and blow down occurs. When the piston is at BDC the transfer port is also uncovered, and the compressed charge in the crankcase expands into the cylinder. Some of the remaining exhaust gases are displaced by the fresh charge; because of the flow mechanism this is called ‘loop '. As the piston travels up the cylinder, the piston closes the first transfer port, and then the exhaust port is closed.

PERFORMANCE OF I.C. ENGINES:

Indicated (ηt): Indicated thermal efficiency is the ratio of energy in the indicated power to the fuel energy

t = Indicated Power / Fuel Energy INTERNAL COMBUSTION ENGINE Prepared By- Dr. Manish K. Mistry

Indicated Power (Kw) 3600 t (%)  100 FuelFlow (Kg/Hr)  Calorific Value (KJ/Kg)

Brake thermal efficiency (ηbth): A measure of overall efficiency of the engine is given by the brake thermal efficiency. Brake thermal efficiency is the ratio of energy in the brake power to the fuel energy. Brake Power (Kw) 3600 bth (%)  100 FuelFlow (Kg/Hr)  Calorific Value (KJ/Kg)

Mechanical efficiency (ηm): Mechanical efficiency is the ratio of brake horse power (delivered power) to the indicated horsepower (power provided to the piston).

m = Brake Power / Indicated Power Frictional power = Indicated power – Brake power Following figure gives diagrammatic representation of various efficiencies, Indicated thermal efficiency = B/A Brake thermal efficiency = C/A Mechanical efficiency = C/B

Volumetric efficiency (ηv): The engine output is limited by the maximum amount of air that can be taken in during the suction stroke, because only a certain amount of fuel can be burned effectively with a given quantity of air. Volumetric efficiency is an indication of the ‘breathing’ ability of the engine and is defined as the ratio of the air actually induced at ambient conditions to the swept volume of the engine. In practice the engine does not induce a complete cylinder full of air on each stroke, and it is convenient to define volumetric efficiency as:

INTERNAL COMBUSTION ENGINE Prepared By- Dr. Manish K. Mistry

MassofAirConsumed ηv (%) mass of flow of air to fill swept volume at atmospheric conditions

AirFlow(Kg/Hr) ηv (%) 2 3 3 100 π/4  D L(m ) N(RPM)n AirDen(Kg/m )60

AIR FLOW: For air consumption measurement air box with orifice is used. AirFlow(Kg / Hr)  C  / 4 D2  2g h     3600 d m m air

Where Cd = Coefficient of discharge of orifice D = Orifice diameter in m g = Acceleration due to gravity (m/s2) = 9.81 m/s2 h m = Differential head across orifice (m of water)  m = Density of manometric fluid (kg/m3) = (Water)1000 kg/m3  air = Air density at working condition (kg/m3) = p/RT Where, p= Atmospheric pressure in N/m2 (1 Standard atm. = 1.01325105 N/m2) R= Gas constant = 287 Nm/kgk T= Atmospheric temperature in k

SPECIFIC FUEL CONSUMPTION (SFC): Brake specific fuel consumption and indicated Specific fuel consumption, abbreviated BSFC and ISFC, are the fuel consumptions On the basis of Brake power and Indicated power respectively.

FUEL-AIR (F/A) OR AIR FUEL (A/F) RATIO: The relative proportions of the fuel and air in the engine are very important from standpoint of combustion and efficiency of the engine. This is expressed either as the ratio of the mass of the fuel to that of the air or vice versa.

CALORIFIC VALUE OR HEATING VALUE OR HEAT OF COMBUSTION: It is the energy released per unit quantity of the fuel, when the combustible is burned and the products of combustion are cooled back to the initial temperature of combustible mixture. The heating value so

INTERNAL COMBUSTION ENGINE Prepared By- Dr. Manish K. Mistry

obtained is called the higher or gross calorific value of the fuel. The lower or net calorific value is the heat released when water in the products of combustion is not condensed and remains in the vapour form.

POWER AND MECHANICAL EFFICIENCY: Power is defined as rate of doing work and equal to the product of force and linear velocity or the product of torque and angular velocity. Thus, the measurement of power involves the measurement of force (or torque) as well as speed. The power developed by an engine at the output shaft is called brake power and is given by Power = 2πNT/60,000 in kW Where, T= torque in Nm = WR W = 9.81  Net mass applied in kg. R= Radius in m N is speed in RPM

MEAN EFFECTIVE PRESSURE AND TORQUE: is defined as a hypothetical pressure, which is thought to be acting on the piston throughout the power stroke.

Power in kW = Pm LANn/60000

Where Pm = mean effective pressure L = length of the stroke in m A = area of the piston in m2 N = Rotational speed of engine RPM n= number of revolutions required to complete one engine cycle n= 1 (for two stroke engine) n= 0.5 (for four stroke engine) Thus we can see that for a given engine the power output can be measured in terms of mean effective pressure. If the mean effective pressure is based on brake power it is called brake mean effective pressure (BMEP) and if based on indicated power it is called indicated mean effective pressure (IMEP). Brake Power (KW) 60000 BMEP(N / m2 )  L  A Nn Indicated Power (KW) 60000 IMEP(N / m2 )  L  A N n Similarly, the friction means effective pressure (FMEP) can be defined as FMEP= IMEP – BMEP

BASIC MEASUREMENTS: The basic measurements, which usually should be undertaken to evaluate the performance of an engine on almost all tests, are the following: INTERNAL COMBUSTION ENGINE Prepared By- Dr. Manish K. Mistry

Measurement Of Speed: Following different speed measuring devices are used for speed measurement. 1. Photoelectric/Inductive proximity pickup with speed indicator 2 .Rotary encoder

Measurement of Fuel Consumption I) Volumetric method: The fuel consumed by an engine is measured by determining the volume flow of the fuel in a given time interval and multiplying it by the specific gravity of fuel. Generally a glass burette having graduations in ml is used for volume flow measurement. Time taken by the engine to consume this volume is measured by stopwatch. II) Gravimetric method: In this method the time to consume a given weight of the fuel is measured. Differential pressure transmitters working on hydrostatic head principles can use for fuel consumption measurement.

Measurement of air consumption Air box method: In IC engines, as the air flow is pulsating, for satisfactory measurement of air consumption an air box of suitable volume is fitted with orifice. The air box is used for damping out the pulsations. The differential pressure across the orifice is measured by manometer and pressure transmitter.

Measurement of brake power Measurement of BP involves determination of the torque and angular speed of the engine output shaft. This torque-measuring device is called a dynamometer. The dynamometers used are of following types:

I) Rope brake dynamometer: It consists of a number of turns of rope wound around the rotating drum attached to the output shaft. One side of the rope is connected to a spring balance and the other to a loading device. The power is absorbed in friction between the rope and the drum. The drum therefore requires cooling. Brake power = 2πNT /60,000 in kW Where T= torque= (W-S) R R=D/2, D = is the brake drum diameter, W is the weight and S is the spring scale reading.

II) Hydraulic dynamometer: Hydraulic dynamometer works on the principal of dissipating the power in fluid friction. It consists of an inner rotating member or impeller coupled to output shaft of the engine. This impeller rotates in a casing, due to the centrifugal force developed, tends to revolve with impeller, but is resisted by torque arm supporting the balance weight. The frictional forces between the impeller and the fluid are measured by the spring-balance fitted on the casing. Heat developed due to dissipation INTERNAL COMBUSTION ENGINE Prepared By- Dr. Manish K. Mistry

of power is carried away by a continuous supply of the working fluid usually water. The output (power absorbed) can be controlled by varying the quantity of water circulating in the vortex of the rotor and elements. This is achieved by a moving sluice gate in the dynamometer casing.

III) Eddy current dynamometer: It consists of a stator on which are fitted a number of electromagnets and a rotor disc and coupled to the output shaft of the engine. When rotor rotates eddy currents are produced in the stator due to magnetic flux set up by the passage of field current in the electromagnets. These eddy currents oppose the rotor motion, thus loading the engine. These eddy currents are dissipated in producing heat so that this type of dynamometer needs cooling arrangement. A moment arm measures the torque. Regulating the current in electromagnets controls the load.

Measurement of indicated power There are two methods of finding the IHP of an engine. I) Indicator diagram: A dynamic pressure sensor (piezo sensor) is fitted in the to sense combustion pressure. A rotary encoder is fitted on the engine shaft for crank angle signal. Both signals are simultaneously scanned by an engine indicator (electronic unit) and communicated to computer. The software in the computer draws pressure crank-angle and pressure volume plots and computes indicated power of the engine. Conversion of pressure crank-angle plot to pressure volume plot:

The figure shows crank-slider mechanism. The piston pin position is given by x = r cos  + l cos 

2 From figure r sin  = l sin  and recalling cos  = 1sin 

x  rcos  l / r 1 r /l2 sin2    

REVIEW QUESTIONS 1. List the different instrument to measure the different parameter during the practical session. INTERNAL COMBUSTION ENGINE Prepared By- Dr. Manish K. Mistry

INTERNAL COMBUSTION ENGINE Prepared By- Dr. Manish K. Mistry

GOVERNMENT ENGINEERING COLLEGE, VALSAD MECHANICAL ENGINEERING DEPARTMENT

PRACTICAL 5: TO STUDY ABOUT ENGINE EMISSIONS AND THEIR CONTROL INTERNAL COMBUSTION ENGINE (2161902) B.E. SEM –6th OBJECTIVES:  To understand the emission norms related to engine.  To understand harmful effect of various engine emitted gaseous.

THEORY:

INTRODUCTION TO ENGINE EMISSION All IC engines produce undesirable emissions as a result of combustion. The emissions of concern are unburned hydrocarbons (UHC), carbon monoxide (CO), oxides of nitrogen such as nitric oxide and nitrogen dioxide (NOx), sulfur dioxide, and solid carbon particulates. These emissions pollute the environment and contribute to acid rain, smog odors, and respiratory and other health problems. HC emissions from -powered vehicles include a number of toxic substances such as benzene, polycyclic aromatic hydrocarbons (PAHs), 1,3-butadiene and three aldehydes (formaldehyde, acetaldehyde, acrolein).Carbon dioxide is an emission that is not regulated but is the primary greenhouse gas responsible for global warming.

Exhaust emissions: Exhaust emissions are those which are emitted through the exhaust pipe when the vehicle is running or is started. Hence, the exhaust emissions maybe of 2 types - start up emissions and running emissions. Startup emissions: Emissions when the vehicle is started initially. Based on how long the vehicle had been turned off after use, they may be cold start and hot start. Cold start refers to when the vehicle is started suddenly after a long gap of use, whereas, hot start refers to when the vehicle is started without the vehicle getting enough time to cool off after its previous use. Running emissions: Emissions during normal running of the vehicle. .i.e., when the vehicle is in a hot stabilized mode. Evaporative emissions: These include running losses and hot soak emissions produced from fuel evaporation when an engine is still hot at the end of a trip, and diurnal emissions (daily temperature variations).

INTERNAL COMBUSTION ENGINE Prepared By- Dr. Manish K. Mistry

Exhaust Pollutants The pollutants which are emitted from the exhaust pipe of the automobiles are known as exhaust pollutants. They are formed as a result of combustion of the fuel in the engine. These pollutants are harmful to the atmosphere and living things in particular. The major types of exhaust pollutants are discussed in the following sections.

Nitrogen Oxides:  Combustion under high temperature and pressure emits Nitrogen dioxide.  With enough heat (above 2500ºF / 1370ºC), nitrogen and oxygen in air-fuel mixture combines to form NOx emissions.  It is reddish brown gas.  An engine with high compression ratio, lean air-fuel mixture, and high-temperature will produce high combustion heat, resulting in formation of NOx.  They affect the respiratory system.

Hydrocarbons and Volatile Organic Compounds:  Hydrocarbons result from the incomplete combustion of fuels.  Mostly related to ignition problems.  Their subsequent reaction with the sunlight causes smog and ground level Ozone formation.  VOCs are a special group of Hydrocarbons. They are divided into 2 types – methane and non – methane. Prolonged exposure to some of these compounds (like Benzene, Toluene and Xylene) may also cause Leukemia.  Effect could be eye, throat, and lung irritation, and, possibly cancer.

Sulphur Oxides:  Combustion of petroleum generates Sulfur Dioxide. It is a colorless, pungent and non – flammable gas.  It causes respiratory illness, but occurs only in very low concentrations in exhaust gases. Further oxidation of forms and thus acid rains.

Carbon Monoxide:  It is a product of the incomplete burning of fuel and is formed when Carbon is partially oxidized.  It is an odorless, colorless gas, but is toxic in nature.  It reaches the blood stream to form Carboxyhemoglobin, which reduces the flow of Oxygen in blood.  A rich air-fuel would increase CO; lean air-fuel mixture would lower CO emissions.

Carbon Dioxide: INTERNAL COMBUSTION ENGINE Prepared By- Dr. Manish K. Mistry

 It is an indicator of complete combustion of the fuel.  Although it does not directly affect our health, it is a greenhouse gas which causes global warming.

Lead:  It is a malleable heavy metal. Lead present in the fuel helps in preventing engine knock.  Lead causes harm to the nervous and reproductive systems.  It is a neurotoxin which accumulates in the soft tissues and bones.

Particulate Matter:  These are tiny solid or liquid particles suspended in gas (soot or smoke).  Particulate Matter in higher concentrations may lead to heart diseases and lung cancer.

INTRODUCTION OF NORMS The first emission norms were introduced in India in 1991 for petrol and 1992 for diesel vehicles. These were followed by making the mandatory for petrol vehicles and the introduction of unleaded petrol in the market. On 29 April 1999 the Supreme Court of India ruled that all vehicles in India have to meet Euro I or India 2000 norms by 1 June 1999 and Euro II will be mandatory in the NCR by April 2000. Car makers were not prepared for this transition and in a subsequent judgment the implementation date for Euro II was not enforced. In 2002, the Indian government accepted the report submitted by the Mashelkar committee. The committee proposed a road map for the roll out of Euro based emission norms for India. It also recommended a phased implementation of future norms with the regulations being implemented in major cities first and extended to the rest of the country after a few years. Based on the recommendations of the committee, the National Auto Fuel policy was announced officially in 2003. The roadmap for implementation of the Bharat Stage norms was laid out till 2010. The policy also created guidelines for auto fuels, reduction of pollution from older vehicles and R&D for air quality data creation and health administration.

Need for uniform emission norms The practice of limiting improved emissions standards only to a few cities and to a smaller proportion of urban population has been criticized as violating the fundamental right to healthy life for all. This also does not allow Lorries to move to cleaner fuel and technology and they heavily pollute cities during transit and aggravate pollution in cities. Many persons and establishments try to purchase Bharat Stage III vehicles and fuel from outside city limits in order to take advantage of lower prices, even though these are used in cities.

INTERNAL COMBUSTION ENGINE Prepared By- Dr. Manish K. Mistry

BHARAT STAGE & EURO NORMS

Standard Reference Year Region

India 2000 Euro 1 2000 Nationwide

NCR*, Mumbai, Kolkata, 2001 Chennai

Bharat Stage II Euro 2 2003.04 NCR*, 13 Cities†

2005.04 Nationwide

2005.04 NCR*, 13 Cities† Bharat Stage III Euro 3 2010.04 Nationwide

Bharat Stage IV Euro 4 2010.04 NCR*, 13 Cities†

Bharat Stage V Euro 5 (To Be Skipped)

Bharat Stage VI Euro 6 2020.04 (Proposed) Entire Country

* National Capital Region (Delhi)† Mumbai, Kolkata, Chennai, Bengaluru, Hyderabad, Ahmedabad, Pune, Surat, Kanpur, Lucknow, Sholapur, Jamshedpur And Agra

REVIEW QUESTIONS 1) Explain the effect of different pollutants on human and plant life. 2) What are the basic types of Diesel smoke? What are the ways of controlling Diesel smoke? 3) State and explain engine design and operating modifications to be made in Spark ignition engine to minimize pollution. 4) Write brief notes on: Euro Norms and Testing of IC engine as per IS.

INTERNAL COMBUSTION ENGINE Prepared By- Dr. Manish K. Mistry

GOVERNMENT ENGINEERING COLLEGE, VALSAD MECHANICAL ENGINEERING DEPARTMENT

PRACTICAL 6: TO DETERMINE THE PERFORMANCE OF SINGLE CYLINDER, FOUR STROKE, DIESEL ENGINE INTERNAL COMBUSTION ENGINE (2161902) B.E. SEM –6th OBJECTIVES:  To determine performance parameter of diesel engine.

ENGINE SET UP: Product Engine test setup 1 cylinder, 4 stroke, diesel Engine Type Single cylinder, 4 stroke Diesel, water cooled, Power 5.0 HP at 1500 rpm, Stroke 110 mm, Bore 80 mm. Compression ratio 16.5:1, Capacity 553 cc. Dynamometer Type rope brake, with set of weights Air box M S fabricated with orifice meter and manometer Capacity 6.5 lit with glass fuel metering column Speed indicator Digital with non-contact type speed sensor Temperature sensor Thermo-sensor Water meter For cooling water flow measurement Number of cylinder One Fuel oil Diesel Orifice dia of Air measurement mm Type of dynamometer Rope brake type Outer dia of drum mm Air density kg/m3

PROCEDURE: • Ensure cooling water circulation for brake drum and engine jacket. • Start the set up and run the engine at no load for 4-5 minutes. • Gradually increase the load on the engine • Wait for steady state (for @ 3 minutes) and collect the reading as per data. • Fill up the observations worksheet to get the results and performance plots. • Gradually decrease the load and shut down the engine.

INTERNAL COMBUSTION ENGINE Prepared By- Dr. Manish K. Mistry

ENGINE TEST SET UP (SINGLE CYLINDER, 4 STROKE, DIESEL) S. no. System Constant Value 1. Orifice diameter (m) 2. Drum radius (m) 3. Dead weight (Kg) 4. Co eff. of discharge for orifice ,Cd 0.6 5. Rope diameter (m) 6. Ambient temperature (Deg C) 7. Fuel density(kg/m^3) (diesel) 8. Fuel Calorific value (KJ/kg) 9. Cylinder diameter (m),D 0.08 10. Stroke(m),L 0.11 11. No of cylinders 1 12. No. of rev./cycle 2 13. Specific heat of exhaust(KJ/Kg. Deg K) 1.15

OBSERVATION TABLE:

Spring Water flow Drum Dead Mano Fuel flow Rate balance rate in engine Temperatures Speed weight deflectio weight water jacket (RPM) (Kg) n (mm) Volum Tim (Kg) (LPM) e e T1 T2 T3 T4 T5 T6

RESULT / ANALYSIS TABLE BP BME BSFC BTh.eff. Air Vol A/F Heat Heat by Heat Unacc (Kw) P kg/kwH (%) flow eff Ratio Equi. of jacket by ounte (Bar) (kg/hr (%) work water (%) exhaus d (%) ) (%) t (%)

INTERNAL COMBUSTION ENGINE Prepared By- Dr. Manish K. Mistry

GOVERNMENT ENGINEERING COLLEGE, VALSAD MECHANICAL ENGINEERING DEPARTMENT

PRACTICAL 7: TO DETERMINE THE PERFORMANCE OF FOUR CYLINDER, FOUR STROKE, PETROL ENGINE INTERNAL COMBUSTION ENGINE (2161902) B.E. SEM –6th OBJECTIVES:  To determine performance parameters of engine.  To prepare heat balance sheet of engine.

ENGINE SET UP:

Product Engine test setup 4 cylinder, 4 stroke petrol Engine Type four cylinder, 4 stroke petrol, water cooled, Engine Description 1061cc, 4 cylinder Maximum Power 62 Bhp @ 6000 rpm Maximum Torque 84 Nm @ 3500 rpm Fuel Type Petrol

Dynamometer Type - Electrical Air box M S fabricated with orifice meter and manometer Speed indicator Digital with non-contact type speed sensor Temperature sensor Thermo-sensor Water meter For cooling water flow measurement Number of cylinder Four Orifice dia of Air measurement Outer dia of drum Air density

PROCEDURE: 1. Fill oil in the oil the oil of engine. It should be in between the marks provided on the oil dipstick. If oil level is reduced, add clean oil (sae-40) to the crankcase by opening the cover of valve provided, at the top of the engine. 2. Fill the petrol in petrol tank. 3. Fill the manometer fluid i.e. water, up to half of the height of manometer. 4. Fill the burette with petrol and supply the petrol to the engine by opening the valve provided at the left side of burette. INTERNAL COMBUSTION ENGINE Prepared By- Dr. Manish K. Mistry

5. Switch on Mains power supply to the panel. 6. Open cold water supply to the engine jacket and exhaust calorimeter. 7. Insert the ignition key and turn it in the clockwise direction to ignition on position, which is indicated by an indicator lamp. Turn the ignition switch key further clockwise against the spring pressure to start the engine. As soon as the engine starts, leave the ignition key and it run for 2 minutes under no load condition. 8. When engine start running smoothly, firstly load on engine with the help of Electrical dynamometer. 9. Run the engine for 2 minutes so that it can stabilize. 10. Note the reading of weight on the output shaft of the dynamometer and note the RPM with the help of . 11. For measuring fuel consumption close the petrol supply valve provided on left side of burette so that fuel flows from burette. Note down the time to consume for 10 or 20 ml of petrol 12. Now open the fuel supply valve which refill the burette and continue the petrol supply. 13. Note down the reading of manometer to calculate the air consumption by the engine. 14. Note the temperature of inlet and outlet of the water circulating through the engine jacket with the help of thermocouple. 15. Measure the flow rate of water from water meter with the help of stop watch. 16. Note down the temperature of inlet and outlet of exhaust gases & water circulating through the calorimeter. Measure the flow rate of water with the help of measuring cylinder and stopwatch. 17. Repeat the experiment for different load. 18. Now for the Morse test, cut off the required cylinder by the respective knife switch. Adjust the speed of the engine to its original value by reducing the load from the dynamometer without changing the throttle position. Repeat same procedure for cutting other cylinder by the respective knife switch. 19. The WILLAN’S Line Method Applicable mainly for diesel engines .The curve of fuel consumption rate against torque at constant speeds plots well as a straight line up to 75% of full power. Equal increases in fuel give equal increases in power (combustion efficiency being constant) At zero power, all fuel burned is expended in overcoming mechanical losses. Extrapolation of the Willan’s line to zero fuel consumption gives a measure of friction losses in the engine 20. When the experiment is over firstly engage all cylinder the throttle reduce the load on removing the weights of the dynamometer and reducing the throttle gradually. 21. Turn off the ignition key and remove it from the switch. 22. Then close the fuel and cooling water supply to the engine.

INTERNAL COMBUSTION ENGINE Prepared By- Dr. Manish K. Mistry

ENGINE TEST SET UP (FOUR CYLINDER, 4 STROKE, PETROL) S. no. System Constant Value 1. Orifice diameter (m) 2. Drum radius (m) 3. Dead weight (Kg) 4. Co eff. of discharge for orifice ,Cd 0.6 5. Rope diameter (m) 6. Ambient temperature (Deg C) 7. Fuel density(kg/m^3) (diesel) 8. Fuel Calorific value (KJ/kg) 9. No of cylinders 10. No. of rev./cycle 11. Specific heat of exhaust(KJ/Kg. Deg K) 1.15

OBSERVATION TABLE: Dead Mano Water flow Drum weight Load Fuel flow Rate deflec rate in Temperatures Speed (Kg) (Electrical tion engine water (RPM) (Rope dynamo ) (mm) Vol. Time jacket (LPM) Brake) T1 T2 T3 T4 T5 T6

RESULT / ANALYSIS TABLE BP BME BSFC BTh.eff. Air Vol A/F Heat Heat by Heat Unacc (Kw) P kg/kwH (%) flow eff Rati Equi.of jacket by ounte (Bar) (kg/h (%) o work water (%) exhaus d (%) r) (%) t (%)

INTERNAL COMBUSTION ENGINE Prepared By- Dr. Manish K. Mistry

GOVERNMENT ENGINEERING COLLEGE, VALSAD MECHANICAL ENGINEERING DEPARTMENT

PRACTICAL 8: TO PERFORM MORSE TEST OF FOUR CYLINDERS, FOUR STROKES, PETROL ENGINE WITH ELECTRICAL DYNAMOMETER.

INTERNAL COMBUSTION ENGINE (2161902) B.E. SEM –6th OBJECTIVES:  To perform morse test of engine.  To determine indicated power of multi cylinder engine.

ENGINE SET UP: Product Engine test setup 4 cylinder, 4 stroke petrol Engine Type four cylinder, 4 stroke petrol, water cooled, Engine Description 1061cc, 4 cylinder Maximum Power 62 Bhp @ 6000 rpm Maximum Torque 84 Nm @ 3500 rpm Fuel Type Petrol

Dynamometer Type - Electrical Air box M S fabricated with orifice meter and manometer Speed indicator Digital with non-contact type speed sensor Temperature sensor Thermo-sensor Water meter For cooling water flow measurement Number of cylinder Four Orifice dia of Air measurement Outer dia of drum Air density

EXPERIMENTAL PROCEDURE: 1. Fill oil in the oil the oil sump of engine. It should be in between the marks provided on the oil dipstick. If oil level is reduced, add clean oil (sae-40) to the crankcase by opening the cover of valve provided, at the top of the engine. 2. Fill the petrol in petrol tank. 3. Fill the manometer fluid i.e. water, up to half of the height of manometer. 4. Fill the burette with petrol and supply the petrol to the engine by opening the valve provided at the left side of burette.

INTERNAL COMBUSTION ENGINE Prepared By- Dr. Manish K. Mistry

5. Switch on Mains power supply to the panel. 6. Open cold water supply to the engine jacket and exhaust calorimeter. 7. Insert the ignition key and turn it in the clockwise direction to ignition on position, which is indicated by an indicator lamp. Turn the ignition switch key further clockwise against the spring pressure to start the engine. As soon as the engine starts, leave the ignition key and it run for 2 minutes under no load condition. 8. When engine start running smoothly, firstly load on engine with the help of Electrical dynamometer. 9. Run the engine for 2 minutes so that it can stabilize. 10. Note the reading of weight on the output shaft of the dynamometer and note the RPM with the help of tachometer. 11. For measuring fuel consumption close the petrol supply valve provided on left side of burette so that fuel flows from burette. Note down the time to consume for 10 or 20 ml of petrol 12. Now open the fuel supply valve which refill the burette and continue the petrol supply. 13. Note down the reading of manometer to calculate the air consumption by the engine. 14. Note the temperature of inlet and outlet of the water circulating through the engine jacket with the help of thermocouple. 15. Measure the flow rate of water from water meter with the help of stop watch. 16. Note down the temperature of inlet and outlet of exhaust gases & water circulating through the calorimeter. Measure the flow rate of water with the help of measuring cylinder and stopwatch. 17. Repeat the experiment for different load. 18. Now for the Morse test, cut off the required cylinder by the respective knife switch. Adjust the speed of the engine to its original value by reducing the load from the dynamometer without changing the throttle position. Repeat same procedure for cutting other cylinder by the respective knife switch. 19. The WILLAN’S Line Method Applicable mainly for diesel engines .The curve of fuel consumption rate against torque at constant speeds plots well as a straight line up to 75% of full power. Equal increases in fuel give equal increases in power (combustion efficiency being constant) at zero power, all fuel burned is expended in overcoming mechanical losses. Extrapolation of the Willan’s line to zero fuel consumption gives a measure of friction losses in the engine 20. When the experiment is over firstly engage all cylinder the throttle reduce the load on removing the weights of the dynamometer and reducing the throttle gradually. 21. Turn off the ignition key and remove it from the switch. 22. Then close the fuel and cooling water supply to the engine.

CALCULATION:

1. Brake power (BP) ...HP

2. Fuel consumption (FC) =…………………kgs/sec INTERNAL COMBUSTION ENGINE Prepared By- Dr. Manish K. Mistry

3. Indicated Power (IP) By Willian's Line Method, we can calculate Frictional Power (FP) 4. IP = BP+ FP ……………………………….. KW 5. F.P = (I.P) n – (B.P) n

6. Mechanical Efficiency mech = .

OBSERVATION TABLE

Sr.no. Cylinder Status Speed RPM LOAD (kg) 1 All ON 2 1st CUT 3 2nd CUT 4 3rd CUT 5 4th CUT

MODEL CALCULATIONS:

BP = HP

Indicated Power of n th cylinder (IP)n (IP) n = (BP) - (BP) n-off = ______KW

Indicated power (IP) of the engine: IP = (IP) 1 + (IP) 2 + (IP) 3 + (IP) 3 =______KW

Frictional Power of the Engine (FP): FP = IP – BP = ______KW

Mechanical Efficiency of the engine ( ηm) =

RESULTS: Sr.no. Cylinder No. I.P. (KW) 1 1st 2 2nd 3 3rd 4 4th

INTERNAL COMBUSTION ENGINE Prepared By- Dr. Manish K. Mistry

GOVERNMENT ENGINEERING COLLEGE, VALSAD MECHANICAL ENGINEERING DEPARTMENT

PRACTICAL 9: TO PERFORM WILLAN’S LINE METHOD FOR DIESEL ENGINE.

INTERNAL COMBUSTION ENGINE (2161902) B.E. SEM –6th OBJECTIVES:  To perform willan’s line method test of engine.  To determine indicated power of engine.

ENGINE SET UP: Product Engine test setup _____ cylinder, 4 stroke petrol Engine Type four cylinder, 4 stroke petrol, water cooled, Engine Description ______cc, ____ cylinder Maximum Power _____Bhp @ ______rpm Maximum Torque ______Nm @ ______rpm Fuel Type

Dynamometer Air box Speed indicator Temperature sensor Water meter Number of cylinder Orifice dia of Air measurement Outer dia of drum Air density

EXPERIMENTAL PROCEDURE: 1. Fill oil in the oil the oil sump of engine. It should be in between the marks provided on the oil dipstick. If oil level is reduced, add clean oil (sae-40) to the crankcase by opening the cover of valve provided, at the top of the engine. 2. Fill the petrol in petrol tank. 3. Fill the manometer fluid i.e. water, up to half of the height of manometer. 4. Fill the burette with petrol and supply the petrol to the engine by opening the valve provided at the left side of burette. 5. Switch on Mains power supply to the panel. INTERNAL COMBUSTION ENGINE Prepared By- Dr. Manish K. Mistry

6. Open cold water supply to the engine jacket and exhaust calorimeter. 7. Insert the ignition key and turn it in the clockwise direction to ignition on position, which is indicated by an indicator lamp. Turn the ignition switch key further clockwise against the spring pressure to start the engine. As soon as the engine starts, leave the ignition key and it run for 2 minutes under no load condition. 8. When engine start running smoothly, firstly load on engine with the help of Electrical dynamometer. 9. Run the engine for 2 minutes so that it can stabilize. 10. Note the reading of weight on the output shaft of the dynamometer and note the RPM with the help of tachometer. 11. For measuring fuel consumption close the petrol supply valve provided on left side of burette so that fuel flows from burette. Note down the time to consume for 10 or 20 ml of petrol 12. Now open the fuel supply valve which refill the burette and continue the petrol supply. 13. Note down the reading of manometer to calculate the air consumption by the engine. 14. Note the temperature of inlet and outlet of the water circulating through the engine jacket with the help of thermocouple. 15. Measure the flow rate of water from water meter with the help of stop watch. 16. Note down the temperature of inlet and outlet of exhaust gases & water circulating through the calorimeter. Measure the flow rate of water with the help of measuring cylinder and stopwatch. 17. Repeat the experiment for different load. 18. Now for the Morse test, cut off the required cylinder by the respective knife switch. Adjust the speed of the engine to its original value by reducing the load from the dynamometer without changing the throttle position. Repeat same procedure for cutting other cylinder by the respective knife switch. 19. The WILLAN’S Line Method Applicable mainly for diesel engines .The curve of fuel consumption rate against torque at constant speeds plots well as a straight line up to 75% of full power. Equal increases in fuel give equal increases in power (combustion efficiency being constant) at zero power, all fuel burned is expended in overcoming mechanical losses. Extrapolation of the Willan’s line to zero fuel consumption gives a measure of friction losses in the engine 20. When the experiment is over firstly engage all cylinder the throttle reduce the load on removing the weights of the dynamometer and reducing the throttle gradually. 21. Turn off the ignition key and remove it from the switch. 22. Then close the fuel and cooling water supply to the engine.

CALCULATION:

1. Brake power (BP) ...Watt

2. Fuel consumption (FC) =…………………kg/s 3. Indicated Power (IP) INTERNAL COMBUSTION ENGINE Prepared By- Dr. Manish K. Mistry

By Willian's Line Method, we can calculate Frictional Power (FP) 4. IP = BP+ FP ……………………………….. KW 5. F.P = (I.P) n – (B.P) n

6. Mechanical Efficiency mech = .

OBSERVATION TABLE

OBSERVATION TABLE:

Fuel flow Rate Dead weight (Kg) Drum Speed (RPM) Mano deflection (mm) (Rope Brake) Vol. Time

RESULTS:

INTERNAL COMBUSTION ENGINE Prepared By- Dr. Manish K. Mistry

GOVERNMENT ENGINEERING COLLEGE, VALSAD MECHANICAL ENGINEERING DEPARTMENT

PRACTICAL 10: TO STUDY FUEL SUPPLY SYSTEM OF ENGINES.

INTERNAL COMBUSTION ENGINE (2161902) B.E. SEM –6th OBJECTIVES:  To study and prepare report on the constructional details, working principles and operation of the Fuels supply systems.  To understand basic needs of fuel supply system.

THEORY:

CARBURETORS: A carburetor is a mechanical device on an internal combustion engine, for the purpose of mixing air and gasoline into a combustible fine vapor, in automatically changing proportions, depending on the operating conditions of the engine. As an example, an engine that runs continually at one speed, day in and day out has need only for a carburetor of the simplest construction. One that has only to mix air and gasoline in one fixed ratio. However, when the demands of the engine are changed and it is desirable to run it at variable speeds, the carburetor must mix air and gasoline in different proportions and therefore, its construction must be more complex.

Construction, Working Principle and Operation of : In the part of the carburetor known as the body is located the float bowl or chamber. This chamber is used for the storage of a certain quantity of gasoline. It serves two purposes, namely, to keep all the other circuits of the carburetor supplied with the amount of fuel they need and to absorb the pulsation of the , as it delivers the gasoline to the carburetor. Though its construction is simple, it plays a very important part in the proper functioning of the engine. The float system consists of the following: float chamber or bowl, fuel inlet, needle valve and seat, float, float pin and on some carburetors a float pin retainer, and the float chamber or bowl cover which contains the float chamber vent. The pump system consists of pump cylinder, pump plunger, plunger operating rod, plunger spring, intake check valve, outlet check valve and pump jet. It also contains the throttle system and choke system. A carburetor is a tube attached to the intake port of the engine and open to the atmosphere. On the intake stroke a volume with little to no pressure develops in the combustion chamber. As a result air flows from outside to inside the engine. As the air flows through the carburetor, the fuel is metered, atomized and vaporized. To have available fuel, the carburetor must have a source of fuel. In the float type carburetor this source is the fuel bowel. A pressure difference is also needed to cause the fuel to flow from the fuel

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bowel into the air stream. This is accomplished using a venturi, Bernoulli’s principle and a tube connecting the mouth of the venture to the fuel bowel.

This is a functioning carburetor and it will operate an engine as long as it has a constant load and constant speed. Very few engines operate at a constant load and constant speed. To adjust the rate of fuel flow a throttle is used. When the throttle is in the closed position there is minimum air flow through the carburetor. When the throttle is in the wide open position, there is maximum air flow through the carburetor. To provide a means to adjust maximum fuel flow, a needle valve was added to the orifice in the emulsion tube. A carburetor with this design would function well under varying loads and speeds.

Starting is a different condition; an engine needs a richer fuel-air mixture. This was accomplished by adding a choke. Closing the choke increases the pressure difference between the fuel bowel and the venturi. Once engine starts the choke must be opened to prevent the engine from running too rich. The addition of a choke/primer improved engine starting, but this carburetor still has a problem if the engine needs to idle. When the throttle is in the idle position, almost closed, the area with greatest restriction, and greatest pressure difference, moves from the venturi to the area between the throttle plate and the wall of the tube. This problem was solved with the addition of an idle circuit and idle needle valve. To have constant fuel flow with constant pressure difference the lift, distance from the top of the fuel to the top of the main nozzle, must remain constant. A constant level of fuel is maintained in the fuel bowel by the float, float needle valve and float needle valve seat.

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DIESEL FUEL INJECTION SYSTEMS: The injection system in diesel engines can be of two types as air injection and airless injection. In air injection system the diesel is injected along with the compressed air whereas in airless injection system only the liquid diesel is injected into the cylinder. Construction, Working Principle and Operation of Diesel Fuel Injection Systems: The construction details of diesel fuel injection system are fuel tank, , fuel pump, fuel injector, and nozzle. A fuel tank is used for storage.

The feed pump is used to feed the fuel to filter where fuel can be filtered. A fuel is used to supply precisely metered quantity of diesel under high pressure to the injectors at well-timed instants. A fuel injector is used to inject the fuel in the cylinder in atomized form and in proper quantity. Main components of fuel injectors are nozzle, valve, body and spring. The nozzle is its main part which is attached to the nozzle holder. Entry of fuel in the injector is from the fuel injection pump. Diesel injector nozzles are spring-loaded closed valves that spray fuel directly into the combustion chamber. Injector nozzles are threaded into the cylinder head, one for each cylinder. The top of the injector nozzle has many holes to deliver an atomized spray of diesel fuel into the cylinder.

GASOLINE FUEL INJECTION SYSTEMS: A modern gasoline injection system uses pressure from an electric fuel pump to spray fuel into the engine intake manifold. Like a carburetor, it must provide the engine with the correct air-fuel mixture for specific operating conditions. Unlike a carburetor, however, pressure, not engine vacuum, is used to feed fuel into the engine. This makes the gasoline injection system very efficient. A gasoline injection system has several possible advantages over a carburetor type of fuel system. Some advantages are as follows: 1. Improved atomization: Fuel is forced into the intake manifold under pressure that helps break fuel droplets into a fine mist. 2. Better fuel distribution: Equal flow of fuel vapors into each cylinder. 3. Smoother idle: Lean fuel mixture can be used without rough idle because of better fuel distribution and low-speed atomization.

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4. Lower emissions: Lean efficient air-fuel mixture reduces exhaust pollution. 5. Better old weather drivability: Injection provides better control of mixture enrichment than a carburetor. 6. Increased engine power: Precise metering of fuel to each cylinder and increased air flow can result in more horsepower output. 7. Fewer parts: Simpler, late model, electronic fuel injection system has fewer parts than modern computer-controlled carburetors. There are many types of gasoline injection systems. Before studying the most common ones, you should have a basic knowledge of the different classifications: 1. Single- or Multi-Point Injection 2. Indirect or Direct Injection

The point or location of fuel injection is one way to classify a gasoline injection system. A single-point injection system, also call throttle body injection (TBI), has the injector nozzles in a throttle body assembly on top of the engine. Fuel is sprayed into the top center of the intake manifold.

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A multi-point injection system, also called port injection, has an injector in the port (air-fuel passage) going to each cylinder. Gasoline is sprayed into each intake port and toward each intake valve. Thereby, the term multipoint (more than one location) fuel injection is used. An system sprays fuel into the engine intake manifold. Most gasoline injection systems are of this type.

Direct injection forces fuel into the engine combustion chambers. Diesel injection systems are direct type. So, Gasoline electronic Direct Injection System is classified as multi-point and direct injection systems.

Construction, Working Principle and Operation of Gasoline Fuel Injection Systems: Its construction details consists of parts as fuel tank, electric fuel pump, fuel filter, , and pressure sensor, electronic injectors and fuel line.  Fuel tank is safe container for flammable liquids and typically part of an engine system in which the fuel is stored and propelled (fuel pump) or released (pressurized gas) into an engine.  An electric fuel pump is used on engines with fuel injection to pump fuel from the tank to the injectors. The pump must deliver the fuel under high pressure (typically 30 to 85 psi depending on the application) so the injectors can spray the fuel into the engine. Electric fuel pumps are usually mounted inside the fuel tank.  The fuel filter is the fuel system's primary line of defense against dirt, debris and small particles of rust that flake off the inside of the fuel tank. Many filters for fuel injected engines trap particles as small as 10 to 40 microns in size. Fuel filter normally made into cartridges containing a filter paper.

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 In automotive electronics, electronic control unit (ECU) is a generic term for any embedded system that controls one or more of the electrical systems or subsystems in a motor vehicle. An (ECU), also known as power-train control module (PCM), or engine control module (ECM) is a type of electronic control unit that determines the amount of fuel, ignition timing and other parameters an internal combustion engine needs to keep running. It does this by reading values from multidimensional maps which contain values calculated by sensor devices monitoring the engine. Control of fuel injection: ECU will determine the quantity of fuel to inject based on a number of parameters. If the throttle pedal is pressed further down, this will open the throttle body and allow more air to be pulled into the engine. The ECU will inject more fuel according to how much air is passing into the engine. If the engine has not warmed up yet, more fuel will be injected. Control of ignition timing: A spark ignition engine requires a spark to initiate combustion in the combustion chamber. An ECU can adjust the exact timing of the spark (called ignition timing) to provide better power and economy. Control of idle speed: Most engine systems have idle speed control built into the ECU. The engine RPM is monitored by the crankshaft position sensor which plays a primary role in the engine timing functions for fuel injection, spark events, and valve timing. Idle speed is controlled by a programmable throttle stop or an idle air bypass control .

 The term "common rail" refers to the fact that all of the fuel injectors are supplied by a common fuel rail which is nothing more than a pressure accumulator where the fuel is stored at high pressure. This accumulator supplies multiple fuel injectors with high pressure fuel.  The fuel injectors are typically ECU-controlled. When the fuel injectors are electrically activated a hydraulic valve (consisting of a nozzle and plunger) is mechanically or hydraulically opened and fuel is sprayed into the cylinders at the desired pressure. Since the fuel pressure energy is stored remotely and the injectors are electrically actuated the injection pressure at the start and end of injection is very near the pressure in the accumulator (rail), thus producing a square injection rate. If the accumulator, pump, and plumbing are sized properly, the injection pressure and rate will be the same for each of the multiple injection events. The injectors can survive the excessive temperature and pressure of combustion by using the fuel that passes through it as a coolant. The electronic fuel injector is normally closed, and opens to inject pressurized fuel as long as INTERNAL COMBUSTION ENGINE Prepared By- Dr. Manish K. Mistry

electricity is applied to the injector's coil. When the injector is turned on, it opens, spraying atomized fuel at the combustion chamber. Depending on engine operating condition, injection quantity will vary.  Fuel line hoses carry gasoline from the tank to the fuel pump, to the fuel filter, and to the fuel injection system. While much of the fuel lines are rigid tube, sections of it are made of rubber hose, which absorb engine and road vibrations.

REVIEW QUESTIONS 1. Explain SOLEX type carburetor with neat sketch 2. Explain MPFI system with neat sketch 3. Explain GDI system with neat sketch 4. Explain CRDi system with neat sketch.

INTERNAL COMBUSTION ENGINE Prepared By- Dr. Manish K. Mistry