DOCSLIB.ORG

Chapter 5 Air and Fuel Introduction T Alrayyes Introduction

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

Chapter 5 Air and Fuel introduction T Alrayyes Introduction • This chapter describes intake systems of engines-how air and fuel are delivered into the cylinders. • The object of the intake system is to deliver the proper amount of air and fuel accurately and equally to all cylinders at the proper time in the engine cycle. • Flow into an engine is pulsed as the intake valves open and close, but can generally be modelled as quasi-steady state flow. • The intake system consists of an • Intake manifold. • Throttle. • Intake valves. • Fuel injectors or a carburettor to add fuel. • The intake manifold has historically been manufactured from aluminum or cast iron, but use of composite plastic materials is gaining popularity Inlet manifold CFD analysis CFD animation for inlet manifold • https://www.youtube.com/watch?v=XHpZY5pI800 • https://www.youtube.com/watch?v=lLpmTbqYkJs Intake manifold • Intake manifold is designed to deliver air to the engine through pipes (runners) to each cylinder. • The inside diameter of the runners are controlled by two factors: • Large enough to have high volumetric efficiency and low flow resistance • Small enough to assure high velocity and turbulence: this enhance the ability to carry fuel droplet and increase evaporation and fuel mixing. • Active intake manifolds (Variable-length intake manifold): are used in some engines were runners can change its length and diameter for different engine speeds • At low speed: the air is directed through longer, smaller diameter runners to keep the velocity high and to assure proper mixing of air and fuel. • At high engine speeds: shorter, larger diameter runners are used, which minimizes flow resistance but still enhances proper mixing. • Variable-length intake manifold • Two and three stages Variable-length intake manifold • http://www.dailymotion.com/video/xz09fn_variable- intake-manifold-systems_auto Improvement in torque figures due to change in runners length and diameter Throttle • The amount of air in SI Engine is controlled using a throttle valve((butterfly valve). • Usually located at the upstream end. • https://www.youtube.com/watch?v=wmrvnZT 4aDU • In the inlet manifold, the fuel injectors can be mounted : • At the inlet of the manifold (throttle body injection) (a) • By the intake valves of each cylinder (multipoint port injection) (b) • in the cylinder head (CI engines and modern two-stroke cycle and some four-stroke cycle SI automobile engines) (c). throttle body injection multipoint port injection For the throttle body injection: • The further upstream the fuel is added, the more time there is to evaporate the fuel droplets and to get proper mixing of the air and fuel vapor. • However, this also reduces engine volumetric efficiency by displacing incoming air with fuel vapor. • Early fuel addition also makes it more difficult to get good cylinder-to-cylinder AF consistency because of the asymmetry of the manifold and different lengths of the runners. • When the fuel is injected: it transfers into small droplet(atomized) due to the injector pressure and the turbulence. • https://www.youtube.com/watch?v=xwjqLgUfcq8 • The above is the most favourable condition that the fuel is at. • Better atomization allows for a more complete burn of all the fuel and helps reduce engine knock by enlarging the flame front. Problem associated with throttle position injection • Due to electrostatic forces some of the fuel will form into pools along the walls of the manifold, or may converge into larger droplets in the air • Both actions are undesirable because they create inconsistencies in the air- fuel ratio. • liquid particles will not always flow at the same velocity as the air and will not flow around corners as readily. larger droplets deviating more than smaller ones. • The third way fuel flows through the manifold is in a thin liquid film along the walls. This film occurs because gravity separates some droplets from the flow, and when other droplets strike the wall where the runner executes a corner. • Using gasoline is another problem when using throttle position injection. • Gasoline components evaporate at different temperatures and at different rates. • Different composition between vapour in the air and gasoline droplet carried by air or the liquid film on the manifold • Different composition will be carried out to the cylinder • This particularly bad for knock behaviour as one of the cylinders will have a worse knock behaviour. • Usually, when the knock number is quoted, it is based on the worse cylinder • Vaporisation rate is also affected by the throttling position as the inlet pressure will change with its position. • All the above problem are sorted when multiport fuel injection is used. Volumetric efficiency of an Engine • Obviously , the engine designer is aiming for the maximum engine efficiency • There will be a certain speed where the engine is going to get its maximum efficiency decreasing as the speed is getting higher or lower • There are few parameters that affect the engine volumetric efficiency: • Fuel used • Inlet charge temperature • Valves overlap • Fluid friction losses • Choked flow • Closing intake valve after BDC • Intake tuning • Exhaust residual • EGR Volumetric efficiency Fuel • Most Gasoline Engine have a lower than 100% volumetric efficiency due to gasoline vapour • The gasoline vapour displace some of the air and reduce the volumetric efficiency • Two factors that cause the fuel to affect the volumetric efficiency : 1. Injection position 2. Type of fuel Injection position/fuel delivery system • The volumetric efficiency of carburettors or throttle injection position is far lower than that of multipoint injectors or Direct injection. • This is because no air is displaced by fuel vapour • When multipoint injectors or Direct injection is used there is no need to have a high speed and high turbulence(lower diameter and longer runner to increase friction). • The above will increase the volumetric efficiency even further because the biggest possible runner diameter will be used. • Note: Although the later the injection in the intake manifold the better the volumetric efficiency, late injection might mean that the fuel didn’t mix well and could compromise combustion quality. May be this isn’t the case in modern engines Fuel type • Alcohol: lower AFR for Alcohol means that more fuel is needed and this will reduce Volumetric efficiency. • Alcohol on the other hand have a higher latent heat of vaporisation which will have a cooling effect that might balance the lower AFR. • Gaseous fuel: like Hydrogen and methane displace more fuel that liquid fuel. Intake charge temperature, heat transfer high temperature • Intake runners especially metal ones are hotter than the outside surface • This result in increasing the temperature of the air getting into the cylinder, decreasing density and subsequently mass of air coming inot the cylinder • At lower speed, the intake charger take longer to pass through the runner, i.e. it get hotter. This will explain partly why are we seeing a reduction in volumetric efficiency at low speed. • Water cooling. Valve overlap • Intake valves start to open some where between 10° to 25° bTDC and should be fully open by TDC to get the maximum flow in. • Intake normally finish closing about 40° to 50° aBDC. https://www.youtube.com/watch?v=cAlw9RpTZ4I Valve overlap • V Valve overlap • There is usually an overlap between the exhaust valve closing and inlet valve opening at the TDC • Some exhaust is pushed back into the inlet manifold, then come back during the induction stroke causing a reduction in the volumetric efficiency. • For a fixed overlap, the problem is at its maximum when the engine is at low speed: • More time for the exhaust to get into the cylinder • The above can explain the reduction in Volumetric efficiency at low speed. Intake Valve opening bTDC • As mentioned earlier Intake valves start to open some where between 10° to 25° bTDC and should be fully open by TDC to get the maximum flow in. • In most engines, the engine speed is set for one engine speed, with volumetric losses happening at higher or lower speed. • At lower speed, the intake valve opens too early and increase overlap duration time as mentioned earlier • At higher than design speed the intake manifold opens too late and the intake flow hasn’t been fully established at TDC Closing the intake valve After BDC • Timing the closure affect how much air enters the cylinder • During the intake stroke, vacuum is created as a result of increase in volume as the piston moves toward BDC. • The lower pressure in the cylinder compare to the inlet manifold causes the air to move to the cylinder • As the piston reach BDC the vacuum is still there and air is still drawn to the cylinder. • Then the air is compressed and the pressure inside the cylinder start to increase. • That’s why closing the inlet valve at BDC will reduce volumetric efficiency as the air still can be drawn in after BDC (vacuum and subsequently pressure difference still exist) • To get the maximum volumetric efficiency, Ideally the IVC when the in- cylinder pressure is equal to the Manifold pressure • To get the maximum volumetric efficiency: the timing for the inlet valve closure is dependent on engine speed: • At higher speed the IVC later in the cycle (later after BDC), this because of greater pressure drop across the valve due to higher flow rate of air. In addition, there is less real cycle time at high speed • At lower speed IVC should be closed early after BDC (the pressure between the inlet manifold and in cylinder equalise earlier). As the pressure difference between the inlet and incylinder is lower as the engine speed is lower • In most engines the intake valve closure position is controlled by the cam and fixed in one position • That explains the high volumetric efficiency at certain speed and it gets lower as the speed increase or decrease.
Recommended publications
  • Mean Value Modelling of a Poppet Valve EGR-System

    Mean Value Modelling of a Poppet Valve EGR-System

    Mean value modelling of a poppet valve EGR-system Master’s thesis performed in Vehicular Systems by Claes Ericson Reg nr: LiTH-ISY-EX-3543-2004 14th June 2004 Mean value modelling of a poppet valve EGR-system Master’s thesis performed in Vehicular Systems, Dept. of Electrical Engineering at Linkopings¨ universitet by Claes Ericson Reg nr: LiTH-ISY-EX-3543-2004 Supervisor: Jesper Ritzen,´ M.Sc. Scania CV AB Mattias Nyberg, Ph.D. Scania CV AB Johan Wahlstrom,¨ M.Sc. Linkopings¨ universitet Examiner: Associate Professor Lars Eriksson Linkopings¨ universitet Linkoping,¨ 14th June 2004 Avdelning, Institution Datum Division, Department Date Vehicular Systems, Dept. of Electrical Engineering 14th June 2004 581 83 Linkoping¨ Sprak˚ Rapporttyp ISBN Language Report category — ¤ Svenska/Swedish ¤ Licentiatavhandling ISRN ¤ Engelska/English ££ ¤ Examensarbete LITH-ISY-EX-3543-2004 ¤ C-uppsats Serietitel och serienummer ISSN ¤ D-uppsats Title of series, numbering — ¤ ¤ Ovrig¨ rapport ¤ URL for¨ elektronisk version http://www.vehicular.isy.liu.se http://www.ep.liu.se/exjobb/isy/2004/3543/ Titel Medelvardesmodellering¨ av EGR-system med tallriksventil Title Mean value modelling of a poppet valve EGR-system Forfattare¨ Claes Ericson Author Sammanfattning Abstract Because of new emission and on board diagnostics legislations, heavy truck manufacturers are facing new challenges when it comes to improving the en- gines and the control software. Accurate and real time executable engine models are essential in this work. One successful way of lowering the NOx emissions is to use Exhaust Gas Recirculation (EGR). The objective of this thesis is to create a mean value model for Scania’s next generation EGR system consisting of a poppet valve and a two stage cooler.
  • Engine Block Materials and Its Production Processes

    Engine Block Materials and Its Production Processes

    ENGINE BLOCK MATERIALS AND ITS PRODUCTION PROCESSES 2.2 THE CAST IRON MONOLITHIC BLOCK The widespread use of cast iron monolithic block is as a result of its low cost and its formidability. This type of block normally comes as the integral type where the engine cylinder and the upper crankcase are joined together as one. The iron used for this block is the gray cast iron having a pearlite-microstructure. The iron is called gray cast iron because its fracture has a gray appearance. Ferrite in the microstructure of the bore wall should be avoided because too much soft ferrite tends to cause scratching, thus increasing blow-by. The production of cast iron blocks using a steel die is rear because its lifecycle is shortened as a result of the repeated heat cycles caused by the molten iron. Sand casting is the method widely used in the production of cast iron blocks. This involves making the mould for the cast iron block with sand. The preparation of sand and the bonding are a critical and very often rate-controlling step. Permanent patterns are used to make sand molds. Usually, an automated molding machine installs the patterns and prepares many molds in the same shape. Molten metal is poured immediately into the mold, giving this process very high productivity. After solidification, the mold is destroyed and the inner sand is shaken out of the block. The sand is then reusable. The bonding of sand is done using two main methods: (i) the green sand mold and (ii) the dry sand mold.
  • Sbd Fuel Injection Assembly and Set up Instructions 2.0L Vauxhall High Specification Taper Throttle Kit

    Sbd Fuel Injection Assembly and Set up Instructions 2.0L Vauxhall High Specification Taper Throttle Kit

    SBDMotorsport April 2013 SBD FUEL INJECTION ASSEMBLY AND SET UP INSTRUCTIONS 2.0L VAUXHALL HIGH SPECIFICATION TAPER THROTTLE KIT SBD would like to thank you for choosing the taper throttle injection kit. The tapered throttle body system which Richard Jenvey and Steve Broughton of SBD Motorsport have developed back in 1995 for the 2.0L XE originally at that time for a touring car project which has been so successful, even spawning many copies. We decided that the fact that the 2.0L XE was still very popular, that is was time to look at the design again which everything that we had learnt in developing the Hayabusa and Duratec high specification throttle bodies. We contacted Jenvey Dynamics again, who have helped us to develop all our own special throttle body projects over the years and started designing a new intake system to suit the 2.0L XE as well as it’s larger capacity versions, 2.2L, 2.3L, 2.4L & 2.5L which are now being built. The tapered throttle body has a 54mm entry tapering down to 52mm butterfly. The taper then continues on through the throttle body then into the manifold and down to the cylinder head. The port shape we have developed to match up with our high specification CNC ported cylinder head, this means the inlet manifold should not require any porting when mated to one of these cylinder heads. The injectors are now mounted underneath the throttle body pointing at an upwards direction at the correct angle so that upon butterfly opening high gas speed is achieved allowing very fast throttle response.
  • Section 02 - Block Basics

    Section 02 - Block Basics

    Block Basics – Section 2 Section 02 - Block Basics 2.0 Small Block 330 & 350 Block Key Differences. The key differences between the 330 and 350 are the 350’s larger bore and the Generation 1 Cast Iron Small Block V-8 Facts 330’s forged crank. General. In 1964 Olds replaced their small block 215 V8 with 1964 – 1966 Valve Lifter Angle. All 1964–1966 blocks used a a cast iron block of completely new design. The 330 V-8 different valve lifter angle of attack on the cam (45). Thus shared none of its engine block architecture with that of the 1964–1966 330 blocks CANNOT USE 1967 AND LATER 215 V-8 and the 225 V-6 sourced from Buick. The engine CAMS. All 1964–1966 cams WILL NOT WORK in 1967 and was no longer aluminum, but cast iron, as weight became later blocks. Later blocks used a 39 lifter angle. Blocks with less of a factor with the engine going into both the larger a “1” or “1A” cast up near the oil filler tube used the 45 lifter mid-sized F-85s, Cutlasses and the full-size Jetstars angle and should be avoided, if possible. introduced in that year. The engine was designed as a replacement for the 215, but was cast iron and enlarged in Early 330 Rocker Arms. The first run of 330 blocks was anticipation of the growth in size of the mid-size cars, where equipped with rocker arms similar to the previous 394 block it was to be primarily used and as the workhorse for the that traces its heritage back to 1949.
  • Diesel Strategy Overview

    Diesel Strategy Overview

    Diesel Strategy Overview Diesel Strategy Overview Status: Confidential Issue Date: 1st Sept 2014 Email: [email protected] Telephone: Tel: +1 (734) 656 0140 Address: Pi Innovo LLC 47023 W. Five Mile Road, Plymouth, MI 48170-3765, USA Incorporated in Delaware 20-5693756 Revision History see version control tool Abstract This document describes the functionality contained in the diesel common rail engine control strategies, discusses where the strategies have been used, and answers common questions customers have about them. Confidential Page 2 of 13 Contents 1. Introduction and Scope 5 2. Software Environment 5 3. Diesel Engine Components 5 4. Control Architecture 6 5. Functional Behavior 7 5.1 Torque Domain 7 5.1.1 Driver Request 7 5.1.2 Idle Speed Control 7 5.1.3 Engine Speed Limiter 7 5.1.4 The Engine Speed Limiter provides rev-limit functionality by reducing torque to provide a smooth limit rather than the sharp limit achieved by cutting cylinders.CAN Torque Requests 7 5.1.5 Engine Loads Model 8 5.1.6 Torque Governor 8 5.2 Air Charge Estimate 8 5.3 Air Controls 8 5.3.1 EGR Demand 8 5.3.2 Boost Pressure Control 9 5.4 Fuel Controls 9 5.4.1 Fuel Rail Pressure Control 9 5.4.2 Injection Quantities to Durations 9 5.4.3 Cylinder Balancing 9 5.4.4 Deceleration Fuel Shut Off 10 5.4.5 Injector Compensation 10 5.5 Miscellaneous Controls 10 5.5.1 Engine Running Mode 10 5.5.2 Glow Plug Controls 10 5.5.3 Cooling Fan Control 10 5.5.4 Manual Calibration Override 10 5.5.5 CAN Communications 11 5.5.6 Diagnostics 11 5.5.6.1 Out of Range 11 Confidential Page 3 of 13 5.5.6.2 Rationality 11 5.5.6.3 Misfire detection 11 6.
  • How a Fuel Injection System Works | How a Car Works 10/5/20, 11�28 AM How a Fuel Injection System Works

    How a Fuel Injection System Works | How a Car Works 10/5/20, 1128 AM How a Fuel Injection System Works

    How a fuel injection system works | How a Car Works 10/5/20, 1128 AM How a fuel injection system works For the engine to run smoothly and efficiently it needs to be provided with the right quantity of fuel /air mixture according to its wide range of demands. A fuel injection system Petrol-engined cars use indirect fuel injection. A fuel pump sends the petrol to the engine bay, and it is then injected into the inlet manifold by an injector. There is either a separate injector for each cylinder or one or two injectors into the inlet manifold. Traditionally, the fuel/air mixture is controlled by the carburettor , an instrument that is by no means perfect. Its major disadvantage is that a single carburettor supplying a four- cylinder https://www.howacarworks.com/basics/how-a-fuel-injection-system-works Page 1 of 7 How a fuel injection system works | How a Car Works 10/5/20, 1128 AM engine cannot give each cylinder precisely the same fuel/air mixture because some of the cylinders are further away from the carburettor than others. One solution is to fit twin-carburettors, but these are difficult to tune correctly. Instead, many cars are now being fitted with fuel-injected engines where the fuel is delivered in precise bursts. Engines so equipped are usually more efficient and more powerful than carburetted ones, and they can also be more economical, as well as having less poisonous emissions . Diesel fuel injection The fuel injection system in petrolengined cars is always indirect, petrol being injected into the inlet manifold or inlet port rather than directly into the combustion chambers .
  • Combined Effect of Inlet Manifold Swirl and Piston Head Configuration in a Constant Speed Four Stoke Diesel Engine V

    Combined Effect of Inlet Manifold Swirl and Piston Head Configuration in a Constant Speed Four Stoke Diesel Engine V

    International Journal of Innovative Technology and Exploring Engineering (IJITEE) ISSN: 2278-3075, Volume-8 Issue-11, September 2019 Combined Effect Of Inlet Manifold Swirl And Piston Head Configuration In A Constant Speed Four Stoke Diesel Engine V. V.NagaDeepthi , K.GovindaRajulu Abstract: The internal combustion engine manifold has a subsystem that supplies the fresh A/F mixture to the engine cylinders where the fuel is combusted. For efficient combustion of charge, the walls of the intake manifold must be smooth / polished to minimize any side resistance. To redesign the inlet port of a small internal combustion engine, to increase the production of turbulence by a swirl. A good swirl promotes more rapid combustion and improves efficiency. The CI engine has a piston shaped flat on the crown and a concave combustion chamber, with this geometry we are driving the engine. But here the A/F ratio mixture cannot mix properly. To avoid this we make piston geometry changes. The main objective of this project is that three new technologies have been adopted here. The first stage is varying the diameter of the convergence - the divergent nozzle. The second stage is the change on the piston head and the Figure 1: Valve Parts of the Inlet and Exhaust last stage is replacing the inlet and exhaust valve with pitch 0.5. Mm to 2 mm and the cut thread depth is 4 mm and three threads The reduced dilution reduces the amount of un burnt per inch. All of these techniques aim to investigate performance mixture/charge inside the chamber which reduces the techniques to increase air flow to achieve improved engine hydrocarbon emissions coming out of the engine.
  • 1,120,118, Patented Dec. 8,1914

    1,120,118, Patented Dec. 8,1914

    E. H. & H. H. ASHLOOK. AUXILIARY AIR INLET DEVICE FOR INTERNAL ‘COMBUSTION ENGINES. APPLICATION FILED NOW 19, 1913. 1,120,118, Patented Dec. 8,1914 Attorneys WTTED STATES PATENT OFFTCE. ERNEST H. ASHLOGK AND HENRY H. ASHLOGK, OF SAN DIEGO, CALIFORNIA. AUXILIARY AIR-INLET DEVICE FOR INTERNAL-COMBUSTION ENGINES. 1,120,118. Speci?cation of Letters Patent. Patented Dec. 8, 1914. Application ?led November 19, 1913. Serial No. 801,910. To all whom it may concern .' through and with which opening my i1n~ Be it known that we, ERNnsT H. AsnLocK, proved device communicates. and HENRY H. AsHLooK, citizens of the An elbow 7 is externally threaded at one United States, residing, at San Diego, in the end as at 8 and to which is secured the yoke 5 county of San Diego and State of Cali 9. The yoke 9 embraces the fuel inlet mani 60 fornia, have invented a new and useful fold 4 therebetwecn and is held rigidly Auxiliary Air-Inlet Device for Internal~ thereto by the curved bolt 10. The extreme . Combustion Engines, of which the follow end of the elbow 7 is beveled as at 11 and ing is a speci?cation. effects an air-tight joint with the side walls of the opening (3 of the fuel inlet manifold. 65 10 This invention relates to an attachment for internal combustion engines and more The remote end of the elbow 7 is also ex particularly to a device for supplying either ternally threaded as at 12 and to which is cold or heated air to the inlet manifold be secured the valve chamber or casing 13.
  • E Series Valves and Manifolds Introduction

    E Series Valves and Manifolds Introduction

    Instrumentation Products E Series Valves and Manifolds Introduction Introduction The AS-Schneider Group with its headquarters in Germany is one of the World‘s Leading Manufacturers of Instrumentation Valves and Manifolds. AS-Schneider offers a large variety of E Series Valves and Manifolds as well as numerous accessories needed for the instrumentation installations globally. Selection can be made from a comprehensive range of bodies with a variety of connections and material options, optimising installation and access opportunities. Many of the valves shown in this catalogue are available from stock or within a short period of time. The dimensions shown in this catalogue apply to standard types – very often 1/2 NPT treaded. If you need the dimensions for your individual type please contact the factory. Note: Not every configuration which can be created in the ordering information is feasible / available. Continuous product development may from time to time necessitate changes in the details contained in this catalogue. AS-Schneider reserves the right to make such changes at their discretion and without prior notice. All dimensions shown in this catalogue are approximate and subject to change. 2 Introduction Service Portal // Digital Product Pass AS-Schneider Contents Introduction | page 2 Contents | page 3 General Features | page 4 Valve Head Unit Options | page 5-11 Connections | page 12-13 Hand Valves | page 14-15 Gauge Valves | page 16-17 Multiport Gauge Valves | page 18-19 Block & Bleed and Double Block & Bleed Manifolds | page 20-21
  • United States Patent (19) 11 Patent Number: 5,950,587 Sattler Et Al

    United States Patent (19) 11 Patent Number: 5,950,587 Sattler Et Al

    USOO5950587A United States Patent (19) 11 Patent Number: 5,950,587 Sattler et al. (45) Date of Patent: Sep. 14, 1999 54 CONTINUOUSLY WARIABLE RUNNER 2682431-A1 4/1993 France. LENGTH MANIFOLD 3825000 A1 2/1989 Germany .......................... 123/184.55 60-224923 11/1985 Japan .................... ... 123/184.55 75 Inventors: Eric R. Sattler, Trenton; Joel S. 2239899 7/1991 United Kingdom ...... ... 123/184.55 Myers, Southgate; Michael J. Haspel, Westland, all of Mich. Primary Examiner Erick R. Solis 73 Assignee: BASF Corporation, Mount Olive, N.J. ASSistant Examiner Brian Hairston Attorney, Agent, or Firm-Ryan W. Massey; James J. Drake 22 Filed: Jul. 22, 1998 A continuously variable runner length manifold is provided (51) Int. Cl. ................................................ FO2B 27/06 for an internal combustion engine. The continuously vari 52 U.S. Cl. .................. 123/184.55; 123/18453 able runner length manifold includes a housing having an 58 Field of Search ........................... 123/184.55, 18453 inlet port and a plurality of outlet ports defined by a plurality of Stacked manifold Sections. A plurality of runner members 56) References Cited are rotatably mounted within the housing. The runner mem bers include wall portions which combine with the housing U.S. PATENT DOCUMENTS to define a plurality of runners in communication with a 4,619,226 10/1986 Ueda et al. ........................ 123s2 MB plenum and a respective one of the outlet ports. The runners 4,699,630 10/1987 Lee et al. ............................... 48/1801 have a length which is continuously variable upon rotation of the runner members relative to the housing. FOREIGN PATENT DOCUMENTS 237755 A2 9/1987 European Pat.
  • Determination of Optimal Valve Timing for Internal Combustion Engines Using Parameter Estimation Method

    Determination of Optimal Valve Timing for Internal Combustion Engines Using Parameter Estimation Method

    130 Determination of optimal valve timing for internal combustion engines using parameter estimation method A. H. Kakaee 1,* and M. Pishgooie 2 1 Assistant Professor, 2 MSc student, Department of Automotive Engineering, Iran University of Science and Technology, Tehran, Iran * [email protected] Abstract In this article determination of appropriate valve timing using sensitivity analysis problem is investigated for a gasoline four stroke engine. In the first part of this study a 4­storke Spark Ignition engine (XU7JP4/L3) including its different systems such as inlet and exhaust manifold, exhaust pipe and engine geometry are modeled using GT­Power software and the model is coupled with MATLAB/Simulink to be able to control input and output parameters. Then in order to find the best model that fits experimental data, sensitivity analysis is performed and the best unknown parameters that can best model the engine are obtained. The input parameters are considered to be the inlet port temperature and pressure, and manifold friction coefficient. The target was achieving the least square error in engine power, torque and fuel consumption. In the second part of the study the optimized model is used for the sensitivity analysis and minimizing the engine specific fuel consumption up to 10 percent reduction in specific fuel consumption as a target. Sensitivity analysis is used for finding the best valve timing in different engine speeds to achieve the target. Keywords: Variable Valve Timing system, GT­Power, MATLAB Simulink, Valve Timing, sensitivity analysis 1. INTRODUCTION mid rpm (1200–3200 rpm) range, and the peak torque improved by an average of 3%.
  • Compacted Graphite Iron for Diesel Engine Cylinder Blocks

    Compacted Graphite Iron for Diesel Engine Cylinder Blocks

    Compacted Graphite Iron for Diesel Engine Cylinder Blocks Wilson Luiz Guesser, Dr Eng - Tupy Fundições and UDESC - Joinville, SC – Brazil – [email protected] Pedro Ventrela Duran, M Sc - Tupy Fundições - Joinville, SC – Brazil – [email protected] Walmor Krause, M Sc - Tupy Fundições - Joinville, SC – Brazil – [email protected] Abstract The recent trends in diesel engines are discussed, and also the consequences in materials selection for engine cylinder blocks. The increasing demand for higher specific power and the need for weight reduction and decrease of emissions require the use of stronger materials for cylinder blocks, opening a promising space for compacted graphite iron (CGI). The properties of CGI are described, in particular those required for engine cylinder blocks (fatigue strength and elastic modulus). Results of mechanical properties from actual castings are presented. As a result of the mechanical properties improvement, some design opportunities are suggested, in order to decrease the weight of the cylinder block. Keywords diesel engines, compacted graphite iron, cylinder blocks 1. Introduction: In a recent paper discussing CGI uses for engine cylinder blocks and heads, S. Dawson (2001) stated that “the Iron Age is just beginning” and we have taken this statement for the present paper. His point of view, added to those from Rizzo (2001), discloses the enormous CGI potential for manufacturing engine components, especially for diesel engines. The growth of diesel engines usage for passenger cars has been remarkable in Europe (see Fig. 1), especially after the introduction of the high-pressure common-rail technology (Buchholz, 2003). This growth is surrounded by requirements as: less fuel consumption, emissions reduction , larger power output and torque, and for passenger cars more compact engines are being required due to space limitations.