Читать книгу Fundamentals of Heat Engines - Jamil Ghojel - Страница 12
ОглавлениеGlossary
Symbols
AArea, air, Helmholtz functionaAcceleration, speed of sound, correlation coefficientBBulk modulus, correlation coefficient, bypass ratioCGas velocity, molar specific heatcMass specific heat, speed of soundDDiameter, degree of reaction in reaction turbinesETotal energy, utilization factor in reaction turbines, modulus of elasticityFForce, thrust, fuelfSpecific thrustGGibbs free energygGravitational accelerationHEnthalpy, heating value of fuelhSpecific enthalpy, blade heightIMoment of inertiaiNumber of cylindersjNumber of strokesKDegrees Kelvin, equilibrium constant, force, mole ratio of hydrogen to carbon monoxideLLengthlLength, blade lengthMQuantity in moles, Mach number, moment of forcemMassMass flow rateNRotational speed in revolution per minute, forcenPolytropic index (exponent), number of molespPressure, cylinder gas pressureQHeat transfer, forceqSpecific heat transferRate of heat transferRRadius, gas constant, crank radiusUniversal gas constantrPressure ratioSEntropy, strokesSpecific entropyTAbsolute temperature, torque, fundamental dimension of timetTime, temperatureUInternal energy, blade speeduSpecific internal energyVVolume, velocity, relative velocityvSpecific volume, piston speedWWorkPowerwSpecific work, blade row width, rate of heat releasexDistance, mass fraction, number of carbon atoms in a fuel, cumulative heat releaseLinear velocityLinear accelerationyNumber of hydrogen atoms in a fuelzNumber of oxygen atoms in a fuel, height above datum
Greek Symbols
αAngle, pressure ratio in constant‐volume combustion, angular accelerationβAngle, volume ratio in constant‐pressure combustionγRatio of specific heats, V‐angle (engine crank)ΔSymbol for differenceδExpansion ratio in an engine cylinderεCompression ratio (volume ratio)εHeat‐exchanger effectivenessηEfficiencyθAngle, crank angleAngular velocityAngular accelerationκCompressibilityλRelative air‐fuel ratioμDynamic viscosity, coefficient of molecular changeνKinematic viscosityΠNon‐dimensional groupρDensity, volume ratio during heat rejection at constant volume (generalized air‐standard cycle)σStress, rounding‐off coefficient in piston engine cyclesτRatio of crank radius to connecting rod lengthφFlow coefficient, crank angle (Wiebe function), equivalence ratioϕAngle (Wiebe function), heat utilization coefficientψLoading coefficient, coefficient of molar changeωAngular velocity, degree of cooling
Subscripts
aAir, actual, total volumebBrakeCCarbon mass fraction in liquid or solid fuelcCompressor, clearance (volume), crankcomCompressor (volume ratio)cpCrank pincrCriticalctCompressor turbinecwCrank webeexitfFuel, frictional, formationgGas, gravimetricHHydrogen mass fraction in liquid or solid fuelhHigheriInlet, intake, indicated, species, inertialLiquid, lowermMeanNNitrogen mole fraction in gaseous fuelnNozzleOMass fraction of oxygen in liquid or solid fuelPProduct of combustionpPiston, propulsivepcCompressor polytropic efficiencyppPiston pinptTurbine polytropic efficiency, power turbineRReactants (air plus fuel)rRod (connecting rod)SSulfur mass fraction in liquid or solid fuelsIsentropic, stoichiometric, swept (volume)tTurbine, total (stagnation) conditionwWhirl (velocity)
Superscripts
gGravimetricReference state (pressure)vVolumetric
Abbreviations
A/FAir‐fuel ratioAFTAdiabatic flame temperatureBDCBottom dead centrecaCrank angleCICompression ignitionF/AFuel‐air ratiobmepBrake mean effective pressureGTGas turbinebsfcBrake specific fuel consumptionimepIndicated mean effective pressureICEInternal combustion engineisfcIndicated specific fuel consumptionmepMean effective pressureNINatural‐induction (engine)ReReynolds numberrpmRevolutions per minuteSISpark ignitionTDCTop dead centreTETTurbine entry temperature
