NOMENCLATURE

Aa1 constantamep mean effective pressure required to drive

the auxiliary componentsA piston area [Chp.l]A area of heat transfer [Chp.14]A average projected area of each particles [Chp.15]A TEL in ml/gal of fuel [Chp.6]A1 cross-sectional area at inlet of the carburettorA2 cross-sectional area at venturi of the carburettorAact actual amount of air in kg for combustion per kg of fuelAf area of cross-section of the fuel nozzle [Chp.8]Af area of fin [Chp.14]Ae effective areaAth theoretical amount of air in kg per kg of fuelA/F air-fuel ratio

Bb1 constantbp brake powerbhp brake horsepowerbmep brake mean effective pressurebs fc brake specific fuel consumptionBDC Bottom Dead Centre

Ccmep mean effective pressure required to drive the

compressor or scavenging pumpC velocity [Chp.6]Cd coefficient of discharge for the orifice [Chp.9]Cda coefficient of discharge for the venturiCdf coefficient of discharge for fuel nozzleCf fuel velocity at the nozzle exitCp specific heat of gas at constant pressureCrel relative chargeCv specific heat at constant volumeCV calorific value of the fuel

Dd cylinder bore diameter [Chp.l]d diameter of orifice [Chp.9]D brake drum diameter

Ee expansion ratioE stored energy [Chp.2]E enrichment [Chp.8]EVC Exhaust Valve ClosingEVO Exhaust Valve Opening

Ff coefficient of frictionfmep frictional mean effective pressurefp frictional powerF forceF/A fuel-air ratioFR relative fuel-air ratio

Gg acceleration due to gravitygc gravitational constantgp gross power

Hh specific enthalpyh pressure difference [Chp.9]h convective heat transfer coefficient [Chp. 14]H enthalpy

Iip indicated powerimep indicated mean effective pressureisfc indicated specific fuel consumptionI intensityI DC Inner Dead CentreIVC Inlet Valve ClosingIVO Inlet Valve Opening

Kk thermal conductivity of gaseski constant [Chp.4]K number of cylindersKac optical absorption coefficient

xxx Nomenclature

Ll characteristic lengthl distance [Chp.16]L strokeLl length of the light path

Mm massm exponent [Chp.14]mep mean effective pressuremmep mechanical mean effective pressure .ma mass flow rate of air .mact actual mass flow rate of air .mth theoretical mass flow rate of airMdel mass of fresh air deliveredMf molecular weight of the fuelM molecular weightMref reference mass

Nn number of power strokesn polytropic index [Chp.2]n number of soot particles per unit volume [Chp.16]N speed in revolutions per minuteNi number of injections per minute [Chp.9]

OODC Outer Dead CentreON Octane Numbers

Pp pressurepmep charging mean effective pressurepp pumping powerPar pure air ratioPbm brake mean effective pressurepe exhaust pressurepi inlet pressurepim indicated mean effective pressurepm mean effective pressurePcyl pressure of charge inside the cylinderPinj fuel pressure at the inlet to injectorPl pressure loss coefficient

Nomenclature xxxi

Ps specific power outputPN performance number

Qq heat transfer .q rate of heat transferQR heat rejectedQs heat supplied

Rr compression ratiorpn relative performance numberrc cut-off ratiorp pressure ratioR length of the moment armR delivery ratio [Chp.20]—R universal gas constantRdel delivery ratio

S–sp mean piston speedsfc specific fuel consumptionS spring scale reading

Tt timeT absolute temperatureT torque [Chp.17]TDC Top Dead CentreTb black body temperatureTf friction torqueTg mean gas temperatureTl load torque

Uu specific internal energyU internal energyUc chemical energyUs stored energy

Vv specific volumeV volume

xxxii Nomenclature

Vch volume of cylinder chargeVcp volume of combustion productsVdel volume of air deliveredVf fuel jet velocityVpure volume of pure airVref reference volumeVres volume of residual gasVret volume of retained air or mixtureVs displacement volumeVs swept volumeVshort short circuiting airVtot total volumeVC clearance volumeVT volume at bottom dead centre

Ww specific weightw work transfer [Chp.8]W net workW weight [Chp.16]W number of quartz windows [Chp.16]W load [Chp.13]WOT Wide Open ThrottleWC compressor workWT turbine workWx external work

Zz height of the nozzle exit [Chp.8]z2 datum height [Chp.2]Z constant

GREEKa air coefficientg ratio of specific heats∆p pressure difference∆T temperature difference between the gas and the walle heat exchanger efficiencyh efficiencyhair std air standard efficiencyhbth brake thermal efficiencyhc compressor efficiencyhch charging efficiency

Nomenclature xxxiii

hith indicated thermal efficiencyhm mechanical efficiencyhrel relative efficiencyhsc scavenging efficiencyht turbine efficiencyhth thermal efficiencyhtrap trapping efficiencyhv volumetric efficiencyq crank angle [Chp.12]q specific absorbance per particle [Chp.16]λ wave length [Chp.16]λ excess air factor [Chp.20]m kinematic viscosity of gasesn dynamic viscosityr densityrf density of fuelf equivalence ratioY magnetic field strengthw angular velocity

xxxiv Nomenclature