3.1 Dimensional Analysis
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Summer 2018 Astron 9 Week 2 FINAL
ORDER OF MAGNITUDE PHYSICS RICHARD ANANTUA, JEFFREY FUNG AND JING LUAN WEEK 2: FUNDAMENTAL INTERACTIONS, NUCLEAR AND ATOMIC PHYSICS REVIEW OF BASICS • Units • Systems include SI and cgs • Dimensional analysis must confirm units on both sides of an equation match • BUCKINGHAM’S PI THEOREM - For a physical equation involving N variables, if there are R independent dimensions, then there are N-R independent dimensionless groups, denoted Π", …, Π%&'. UNITS REVIEW – BASE UNITS • Physical quantities may be expressed using several choices of units • Unit systems express physical quantities in terms of base units or combinations thereof Quantity SI (mks) Gaussian (cgs) Imperial Length Meter (m) Centimeter (cm) Foot (ft) Mass Kilogram (kg) Gram (g) Pound (lb) Time Second (s) Second (s) Second (s) Temperature Kelvin (K) Kelvin (K)* Farenheit (ºF) Luminous intensity Candela (cd) Candela (cd)* Amount Mole (mol) Mole (mol)* Current Ampere (A) * Sometimes not considered a base cgs unit REVIEW – DERIVED UNITS • Units may be derived from others Quantity SI cgs Momentum kg m s-1 g cm s-1 Force Newton N=kg m s-2 dyne dyn=g cm s-2 Energy Joule J=kg m2 s-2 erg=g cm2 s-2 Power Watt J=kg m2 s-3 erg/s=g cm2 s-3 Pressure Pascal Pa=kg m-1 s-2 barye Ba=g cm-1 s-2 • Some unit systems differ in which units are considered fundamental Electrostatic Units SI (mks) Gaussian cgs Charge A s (cm3 g s-2)1/2 Current A (cm3 g s-4)1/2 REVIEW – UNITS • The cgs system for electrostatics is based on the assumptions kE=1, kM =2kE/c2 • EXERCISE: Given the Gaussian cgs unit of force is g cm s-2, what is the electrostatic unit of charge? # 2 ! = ⟹ # = ! & 2 )/+ = g cm/ s1+ )/+ [&]2 REVIEW – BUCKINGHAM’S PI THEOREM • BUCKINGHAM’S PI THEOREM - For a physical equation involving N variables, if there are R independent dimensions, then there are N-R independent dimensionless groups, denoted Π", …, Π%&'. -
Metric System Units of Length
Math 0300 METRIC SYSTEM UNITS OF LENGTH Þ To convert units of length in the metric system of measurement The basic unit of length in the metric system is the meter. All units of length in the metric system are derived from the meter. The prefix “centi-“means one hundredth. 1 centimeter=1 one-hundredth of a meter kilo- = 1000 1 kilometer (km) = 1000 meters (m) hecto- = 100 1 hectometer (hm) = 100 m deca- = 10 1 decameter (dam) = 10 m 1 meter (m) = 1 m deci- = 0.1 1 decimeter (dm) = 0.1 m centi- = 0.01 1 centimeter (cm) = 0.01 m milli- = 0.001 1 millimeter (mm) = 0.001 m Conversion between units of length in the metric system involves moving the decimal point to the right or to the left. Listing the units in order from largest to smallest will indicate how many places to move the decimal point and in which direction. Example 1: To convert 4200 cm to meters, write the units in order from largest to smallest. km hm dam m dm cm mm Converting cm to m requires moving 4 2 . 0 0 2 positions to the left. Move the decimal point the same number of places and in the same direction (to the left). So 4200 cm = 42.00 m A metric measurement involving two units is customarily written in terms of one unit. Convert the smaller unit to the larger unit and then add. Example 2: To convert 8 km 32 m to kilometers First convert 32 m to kilometers. km hm dam m dm cm mm Converting m to km requires moving 0 . -
Dimensional Analysis and the Theory of Natural Units
LIBRARY TECHNICAL REPORT SECTION SCHOOL NAVAL POSTGRADUATE MONTEREY, CALIFORNIA 93940 NPS-57Gn71101A NAVAL POSTGRADUATE SCHOOL Monterey, California DIMENSIONAL ANALYSIS AND THE THEORY OF NATURAL UNITS "by T. H. Gawain, D.Sc. October 1971 lllp FEDDOCS public This document has been approved for D 208.14/2:NPS-57GN71101A unlimited release and sale; i^ distribution is NAVAL POSTGRADUATE SCHOOL Monterey, California Rear Admiral A. S. Goodfellow, Jr., USN M. U. Clauser Superintendent Provost ABSTRACT: This monograph has been prepared as a text on dimensional analysis for students of Aeronautics at this School. It develops the subject from a viewpoint which is inadequately treated in most standard texts hut which the author's experience has shown to be valuable to students and professionals alike. The analysis treats two types of consistent units, namely, fixed units and natural units. Fixed units include those encountered in the various familiar English and metric systems. Natural units are not fixed in magnitude once and for all but depend on certain physical reference parameters which change with the problem under consideration. Detailed rules are given for the orderly choice of such dimensional reference parameters and for their use in various applications. It is shown that when transformed into natural units, all physical quantities are reduced to dimensionless form. The dimension- less parameters of the well known Pi Theorem are shown to be in this category. An important corollary is proved, namely that any valid physical equation remains valid if all dimensional quantities in the equation be replaced by their dimensionless counterparts in any consistent system of natural units. -
Chapter 5 Dimensional Analysis and Similarity
Chapter 5 Dimensional Analysis and Similarity Motivation. In this chapter we discuss the planning, presentation, and interpretation of experimental data. We shall try to convince you that such data are best presented in dimensionless form. Experiments which might result in tables of output, or even mul- tiple volumes of tables, might be reduced to a single set of curves—or even a single curve—when suitably nondimensionalized. The technique for doing this is dimensional analysis. Chapter 3 presented gross control-volume balances of mass, momentum, and en- ergy which led to estimates of global parameters: mass flow, force, torque, total heat transfer. Chapter 4 presented infinitesimal balances which led to the basic partial dif- ferential equations of fluid flow and some particular solutions. These two chapters cov- ered analytical techniques, which are limited to fairly simple geometries and well- defined boundary conditions. Probably one-third of fluid-flow problems can be attacked in this analytical or theoretical manner. The other two-thirds of all fluid problems are too complex, both geometrically and physically, to be solved analytically. They must be tested by experiment. Their behav- ior is reported as experimental data. Such data are much more useful if they are ex- pressed in compact, economic form. Graphs are especially useful, since tabulated data cannot be absorbed, nor can the trends and rates of change be observed, by most en- gineering eyes. These are the motivations for dimensional analysis. The technique is traditional in fluid mechanics and is useful in all engineering and physical sciences, with notable uses also seen in the biological and social sciences. -
Three-Dimensional Analysis of the Hot-Spot Fuel Temperature in Pebble Bed and Prismatic Modular Reactors
Transactions of the Korean Nuclear Society Spring Meeting Chuncheon, Korea, May 25-26 2006 Three-Dimensional Analysis of the Hot-Spot Fuel Temperature in Pebble Bed and Prismatic Modular Reactors W. K. In,a S. W. Lee,a H. S. Lim,a W. J. Lee a a Korea Atomic Energy Research Institute, P. O. Box 105, Yuseong, Daejeon, Korea, 305-600, [email protected] 1. Introduction thousands of fuel particles. The pebble diameter is 60mm High temperature gas-cooled reactors(HTGR) have with a 5mm unfueled layer. Unstaggered and 2-D been reviewed as potential sources for future energy needs, staggered arrays of 3x3 pebbles as shown in Fig. 1 are particularly for a hydrogen production. Among the simulated to predict the temperature distribution in a hot- HTGRs, the pebble bed reactor(PBR) and a prismatic spot pebble core. Total number of nodes is 1,220,000 and modular reactor(PMR) are considered as the nuclear heat 1,060,000 for the unstaggered and staggered models, source in Korea’s nuclear hydrogen development and respectively. demonstration project. PBR uses coated fuel particles The GT-MHR(PMR) reactor core is loaded with an embedded in spherical graphite fuel pebbles. The fuel annular stack of hexahedral prismatic fuel assemblies, pebbles flow down through the core during an operation. which form 102 columns consisting of 10 fuel blocks PMR uses graphite fuel blocks which contain cylindrical stacked axially in each column. Each fuel block is a fuel compacts consisting of the fuel particles. The fuel triangular array of a fuel compact channel, a coolant blocks also contain coolant passages and locations for channel and a channel for a control rod. -
How Are Units of Measurement Related to One Another?
UNIT 1 Measurement How are Units of Measurement Related to One Another? I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot express it in numbers, your knowledge is of a meager and unsatisfactory kind... Lord Kelvin (1824-1907), developer of the absolute scale of temperature measurement Engage: Is Your Locker Big Enough for Your Lunch and Your Galoshes? A. Construct a list of ten units of measurement. Explain the numeric relationship among any three of the ten units you have listed. Before Studying this Unit After Studying this Unit Unit 1 Page 1 Copyright © 2012 Montana Partners This project was largely funded by an ESEA, Title II Part B Mathematics and Science Partnership grant through the Montana Office of Public Instruction. High School Chemistry: An Inquiry Approach 1. Use the measuring instrument provided to you by your teacher to measure your locker (or other rectangular three-dimensional object, if assigned) in meters. Table 1: Locker Measurements Measurement (in meters) Uncertainty in Measurement (in meters) Width Height Depth (optional) Area of Locker Door or Volume of Locker Show Your Work! Pool class data as instructed by your teacher. Table 2: Class Data Group 1 Group 2 Group 3 Group 4 Group 5 Group 6 Width Height Depth Area of Locker Door or Volume of Locker Unit 1 Page 2 Copyright © 2012 Montana Partners This project was largely funded by an ESEA, Title II Part B Mathematics and Science Partnership grant through the Montana Office of Public Instruction. -
Measuring in Metric Units BEFORE Now WHY? You Used Metric Units
Measuring in Metric Units BEFORE Now WHY? You used metric units. You’ll measure and estimate So you can estimate the mass using metric units. of a bike, as in Ex. 20. Themetric system is a decimal system of measurement. The metric Word Watch system has units for length, mass, and capacity. metric system, p. 80 Length Themeter (m) is the basic unit of length in the metric system. length: meter, millimeter, centimeter, kilometer, Three other metric units of length are themillimeter (mm) , p. 80 centimeter (cm) , andkilometer (km) . mass: gram, milligram, kilogram, p. 81 You can use the following benchmarks to estimate length. capacity: liter, milliliter, kiloliter, p. 82 1 millimeter 1 centimeter 1 meter thickness of width of a large height of the a dime paper clip back of a chair 1 kilometer combined length of 9 football fields EXAMPLE 1 Using Metric Units of Length Estimate the length of the bandage by imagining paper clips laid next to it. Then measure the bandage with a metric ruler to check your estimate. 1 Estimate using paper clips. About 5 large paper clips fit next to the bandage, so it is about 5 centimeters long. ch O at ut! W 2 Measure using a ruler. A typical metric ruler allows you to measure Each centimeter is divided only to the nearest tenth of into tenths, so the bandage cm 12345 a centimeter. is 4.8 centimeters long. 80 Chapter 2 Decimal Operations Mass Mass is the amount of matter that an object has. The gram (g) is the basic metric unit of mass. -
Mercury Barometers and Manometers
NBS MONOGRAPH 8 Mercuiy Barometers and Manometers U.S. DEPARTMENT OF COMMERCE NATIONAL BUREAU OF STANDARDS THE NATIONAL BUREAU OF STANDARDS Functions and Activities The functions of the National Bureau of Standards are set forth in the Act of Congress, March 3, 1901, as amended by Congress in Public Law 619, 1950. These include the development and maintenance of the national standards of measurement and the provision of means and methods for making measurements consistent with these standards; the determination of physical constants and properties of materials; the development of methods and instruments for testing materials, devices, and structures; advisory services to government agencies on scientific and technical problems; in- vention and development of devices to serve special needs of the Government; and the development of standard practices, codes, and specifications. The work includes basic and applied research, development, engineering, instrumentation, testing, evaluation, calibration services, and various consultation and information services. Research projects are also performed for other government agencies when the work relates to and supplements the basic program of the Bureau or when the Bureau's unique competence is required. The scope of activities is suggested by the listing of divisions and sections on the inside of the back cover. Publications The results of the Bureau's work take the form of either actual equipment and devices or pub- lished papers. These papers appear either in the Bureau's own series of publications or in the journals of professional and scientific societies. The Bureau itself publishes three periodicals available from the Government Printing Office: The Journal of Research, published in four separate sections, presents complete scientific and technical papers; the Technical News Bulletin presents summary and pre- liminary reports on work in progress; and Basic Radio Propagation Predictions provides data for determining the best frequencies to use for radio communications throughout the world. -
Units of Measurement and Dimensional Analysis
Measurements and Dimensional Analysis POGIL ACTIVITY.2 Name ________________________________________ POGIL ACTIVITY 2 Units of Measurement and Dimensional Analysis A. Units of Measurement- The SI System and Metric System here are myriad units for measurement. For example, length is reported in miles T or kilometers; mass is measured in pounds or kilograms and volume can be given in gallons or liters. To avoid confusion, scientists have adopted an international system of units commonly known as the SI System. Standard units are called base units. Table A1. SI System (Systéme Internationale d’Unités) Measurement Base Unit Symbol mass gram g length meter m volume liter L temperature Kelvin K time second s energy joule j pressure atmosphere atm 7 Measurements and Dimensional Analysis POGIL. ACTIVITY.2 Name ________________________________________ The metric system combines the powers of ten and the base units from the SI System. Powers of ten are used to derive larger and smaller units, multiples of the base unit. Multiples of the base units are defined by a prefix. When metric units are attached to a number, the letter symbol is used to abbreviate the prefix and the unit. For example, 2.2 kilograms would be reported as 2.2 kg. Plural units, i.e., (kgs) are incorrect. Table A2. Common Metric Units Power Decimal Prefix Name of metric unit (and symbol) Of Ten equivalent (symbol) length volume mass 103 1000 kilo (k) kilometer (km) B kilogram (kg) Base 100 1 meter (m) Liter (L) gram (g) Unit 10-1 0.1 deci (d) A deciliter (dL) D 10-2 0.01 centi (c) centimeter (cm) C E 10-3 0.001 milli (m) millimeter (mm) milliliter (mL) milligram (mg) 10-6 0.000 001 micro () micrometer (m) microliter (L) microgram (g) Critical Thinking Questions CTQ 1 Consult Table A2. -
MEMS Metrology Metrology What Is a Measurement Measurable
Metrology • What is metrology? – It is the science of weights and measures • Refers primarily to the measurements of length, MEMS Metrology wetight, time, etc. • Mensuration- A branch of applied geometry – It measure the area and volume of solids from Dr. Bruce K. Gale lengths and angles Fundamentals of Micromachining • It also includes other engineering measurements for the establishment of a flat, plane reference surface What is a Measurement Measurable Parameters • A measurement is an act of assigning a • What do we want to • Pressure specific value to a physical variable measure? • Forces • The physical variable becomes the • Length or distance •Stress measured variable •Mass •Strain • Temperature • Measurements provide a basis for • Friction judgements about • Elemental composition • Resistance •Viscosity – Process information • Roughness • Diplacements or – Quality assurance •Depth distortions – Process control • Intensity •Time •etc. Components of a Measuring Measurement Systems and Tools System • Measurement systems are important tools for the quantification of the physical variable • Measurement systems extend the abilities of the human senses, while they can detect and recognize different degrees of physical variables • For scientific and engineering measurement, the selection of equipment, techniques and interpretation of the measured data are important How Important are Importance of Metrology Measurements? • In human relationships, things must be • Measurement is the language of science counted and measured • It helps us -
Alkali Metal Vapor Pressures & Number Densities for Hybrid Spin Exchange Optical Pumping
Alkali Metal Vapor Pressures & Number Densities for Hybrid Spin Exchange Optical Pumping Jaideep Singh, Peter A. M. Dolph, & William A. Tobias University of Virginia Version 1.95 April 23, 2008 Abstract Vapor pressure curves and number density formulas for the alkali metals are listed and compared from the 1995 CRC, Nesmeyanov, and Killian. Formulas to obtain the temperature, the dimer to monomer density ratio, and the pure vapor ratio given an alkali density are derived. Considerations and formulas for making a prescribed hybrid vapor ratio of alkali to Rb at a prescribed alkali density are presented. Contents 1 Vapor Pressure Curves 2 1.1TheClausius-ClapeyronEquation................................. 2 1.2NumberDensityFormulas...................................... 2 1.3Comparisonwithotherstandardformulas............................. 3 1.4AlkaliDimers............................................. 3 2 Creating Hybrid Mixes 11 2.1Predictingthehybridvaporratio.................................. 11 2.2Findingthedesiredmolefraction.................................. 11 2.3GloveboxMethod........................................... 12 2.4ReactionMethod........................................... 14 1 1 Vapor Pressure Curves 1.1 The Clausius-Clapeyron Equation The saturated vapor pressure above a liquid (solid) is described by the Clausius-Clapeyron equation. It is a consequence of the equality between the chemical potentials of the vapor and liquid (solid). The derivation can be found in any undergraduate text on thermodynamics (e.g. Kittel & Kroemer [1]): Δv · ∂P = L · ∂T/T (1) where P is the pressure, T is the temperature, L is the latent heat of vaporization (sublimation) per particle, and Δv is given by: Vv Vl(s) Δv = vv − vl(s) = − (2) Nv Nl(s) where V is the volume occupied by the particles, N is the number of particles, and the subscripts v & l(s) refer to the vapor & liquid (solid) respectively. -
Planck Dimensional Analysis of Big G
Planck Dimensional Analysis of Big G Espen Gaarder Haug⇤ Norwegian University of Life Sciences July 3, 2016 Abstract This is a short note to show how big G can be derived from dimensional analysis by assuming that the Planck length [1] is much more fundamental than Newton’s gravitational constant. Key words: Big G, Newton, Planck units, Dimensional analysis, Fundamental constants, Atomism. 1 Dimensional Analysis Haug [2, 3, 4] has suggested that Newton’s gravitational constant (Big G) [5] can be written as l2c3 G = p ¯h Writing the gravitational constant in this way helps us to simplify and quantify a long series of equations in gravitational theory without changing the value of G, see [3]. This also enables us simplify the Planck units. We can find this G by solving for the Planck mass or the Planck length with respect to G, as has already been done by Haug. We will claim that G is not anything physical or tangible and that the Planck length may be much more fundamental than the Newton’s gravitational constant. If we assume the Planck length is a more fundamental constant than G,thenwecanalsofindG through “traditional” dimensional analysis. Here we will assume that the speed of light c, the Planck length lp, and the reduced Planck constanth ¯ are the three fundamental constants. The dimensions of G and the three fundamental constants are L3 [G]= MT2 L2 [¯h]=M T L [c]= T [lp]=L Based on this, we have ↵ β γ G = lp c ¯h L3 L β L2 γ = L↵ M (1) MT2 T T ✓ ◆ ✓ ◆ Based on this, we obtain the following three equations Lenght : 3 = ↵ + β +2γ (2) Mass : 1=γ (3) − Time : 2= β γ (4) − − − ⇤e-mail [email protected].