Many devices involve a number of individual processes, each of which are often analyzed in terms of isentropic efficiency. 1–2: isentropic compression in the compressor K, which leads to increased pressure and temperature from the values corresponding to evaporation pe, te to those of the condensation pc, t2 > tc; 2–2′: isobar cooling in the condenser C at pressure pc from the temperature t2 to t2′ = tc; 2′–3: isotherm–isobar condensation in the condenser C at pressure pc and temperature tc; 3–4: isenthalpic lamination in expansion valve EV, leading the refrigerant from State 3 of the liquid at pc, tc in State 4 of wet vapor at pe, te; and. The influence of radiator fan speed on pressure drop (∆Pfan) is modelled using a second order empirical relationship as a function of volume flow rate and fan speed in revolutions per minute from [10]. Copyright © 2021 Elsevier B.V. or its licensors or contributors. It has been assumed that the LP and HP compressor polytropic efficiencies are equal. isentropic compression – ambient air is drawn into the compressor, where it is pressurized (1 → 2). Free PDF. 4.17 . Once compressed, the air is passed through a heat exchanger within which it rejects heat and is cooled to 50 °C. The work transfers of the system are frictionless, and there is no transfer of heat or matter. This reflects the higher temperature achieved during irreversible compression. 1 The polytropic efficiency was converted into an isentropic efficiency to include the effects of compression ratio and specific heat ratio (k = Cp/Cv) for a given refrigerant. The saturated liquid refrigerant at State 3 is throttled to the evaporation pressure by passing it through an expansion valve. Deviations of experimental detonation velocities from theory (Berets, Greene, and Kistiakowsky). To each equilibrium considered there corresponds an equilibrium constant. Compressor efficiency can be defined as the ratio between this enthalpy increase and the actual measured enthalpy increase, i.e. A problem about calling Refprop software with Matlab? Open symbols 1.2-cm. Variation of thermal efficiency with specific work for a practical intercooled gas turbine, where low-pressure (LP) compressor pressure ratio is optimised for maximum specific work. ... 4.1 Volumetric and Isentropic Efficiency of a Compressor … This means that, even if the energy in the gas after compression is passed through a reversible heat engine, it will not be possible to produce as much work as was required to compress the gas. 1−2: isentropic compression in the compressor K, which leads to increased pressure and temperature from the values corresponding for evaporation pe, te to those of the condensation pc, t2 > tc; 2−2': isobar cooling in the condenser C at pressure pc from the temperature t2 to t2' = tc; 2'−3: isothermisobar condensation in the condenser C at pressure pc and temperature tc; 3−3': isobar subcooling in the subcooler SC at pressure pc from the temperature tc to tsc < tc; 3'−4: isenthalpic lamination in expansion valve EV, leading the refrigerant from the three states of the liquid at pc, tc in the four states of the wet vapor at pe, te; 4−1: isothermisobar evaporation in the evaporator E at pressure pe and temperature te. where, variable Eh, u is power consumed or generated, M is mole fraction of component c, isentropic exponent θu is the ratio of heat capacities of gas streams at constant pressure and temperature, εc is specific heat capacity, and c is a set of chemical components. The specific compression work w, in kJ/kg, the specific cooling power q0, in kJ/kg, the specific heat load at condensation qc, in kJ/kg, volumetric refrigerating capacity q0v, in kJ/m3, the coefficient of performance COP are calculated for the previously presented processes as follows: Thermal power (capacity) of heat pump QHP, in kW, is expressed as: The power necessary for the isentropic compression Pis, in kW, may be calculated using the equation: The effective power Pef on the compressor shaft is larger and is defined as: Ioan Sarbu, Calin Sebarchievici, in Solar Heating and Cooling Systems, 2017. Price of a solar panel varies widely in the market. 8.3. The compressor pressure ratio split will be biased towards the higher efficiency compressor. Do we sing exactly the same song? I don't know if I am wrong somewhere, can anyone give some advice? The latter is introduced into equation (22) which is then solved to give an improved value of T2. The dissociation equilibria considered were. Download PDF Package. During this process, work is done by the piston compressing the working fluid. You are right about the reduction in the performance of both heat exchangers and compressor. Wen W. Zhang, ... Qing L. Chen, in Computer Aided Chemical Engineering, 2018. The radiator model has been validated using experimental heat transfer data published by [15] giving an error of less than 5% across a variety of coolant and air flow rates. The compressor power can be calculated by. There will also be heat transfer to and from external sources to the compressed fluid. The dissociation, being a heat absorbing process, increases the specific heat, and since it leads to an increase in the number of moles, increases the specific volume. Isentropic efficiency and volumetric efficiency of a refrigeration compressor are very important for system operations. By continuing you agree to the use of cookies. This ratio is known as the Isentropic Turbine/Compressor/Nozzle Efficiency. Join ResearchGate to find the people and research you need to help your work. Ioan Sarbu, Calin Sebarchievici, in Ground-Source Heat Pumps, 2016. The second and third columns contain the pressure and temperature in the wave. The refrigerant temperature increases during this isentropic compression process to well above the temperature of the surrounding medium. The optimisation of a practical intercooled gas turbine for maximum thermal efficiency may not result in the LP and HP compressor pressure ratios being equal and generally the LP compressor pressure ratio will be much less than the optimum value for minimum compression work. The unknown quantities are p2, v2, T2, and D for which there are four equations. 4−1: isotherm–isobar evaporation in the evaporator E at pressure p0 and temperature t0. These two economic analyses are based on the second law of thermodynamics. Therefore, one should find the rather remarkable result that two inert monatomic gases, differing in atomic weight but identical in their thermal effect, affect the detonation velocity in opposite directions. MANUAL CALCULATION OF ISENTROPICEFFICIENCY FROM ISENTROPIC HEAD AND BHP •Isentropic Head = 9616 m •BHP= 100 hp= 74.6 kW = 74600 W = 74600 kg-m2/s3 •Mass flow rate of gas= 4707 lb/h = 2136.978 kg/h = 0.593 kg/sec •Isentropic Efficiency= Mass flow rate x Polytropic Head x 9.8 m/s2 / BHP = 0.593kg/s x 9616m x 9.8m/s2 / 74600kg-m2/s3 = 0.74909 = 74.909 % •Isentropic Efficiency … Most diesel engines have large pistons and therefore draw more air and fuel, which results in a bigger and more powerful combustion. The refrigerant temperature increases during this isentropic compression process to well above the temperature of the surrounding medium. Hence the irreversibility of the process is given by, This is the negative of the change of availability of the universe (system + surroundings) which is given by. Figure 8.3. [54] for low to high efficiency compressors. Can we find some efficiency data of screw and centrifugal compressors attenuated with running time? Desmond E. Winterbone FEng, BSc, PhD, DSc, FIMechE, MSAE, in Advanced Thermodynamics for Engineers, 1997, Fig. 1. FIG. the turbine work remains the same, while the compression work decreases. ), GUENTHER von ELBE Ph.D. (Berlin), in, Combustion, Flames and Explosions of Gases (Second Edition), The ideal intercooled cycle considers only, System thermal and water balance in an evaporatively cooled PEM fuel cell vehicle, Vehicle Thermal Management Systems Conference Proceedings (VTMS11), Vapour Compression-Based Heat Pump Systems, The basic vapour-compression cycle is considered as one with, Vapor-compression system consists of compressor, condenser expansion valve, and evaporator, connected with refrigerant pipelines. Compression process on a T–s diagram, The work done can be calculated from the steady flow energy equation, giving, The change of availability is given by eqn (2.13b) as, If the process is isentropic, ΔS= 0, and then. Figure 8.4. The refrigerant temperature drops below the temperature of the cold environment during this process. The isentropic efficiency of a compressor or pump is defined as the ratio of the work input to an isentropic process, to the work input to the actual process between the same inlet and exit pressures. In case of thermal dissociation the last quantities depend on pressure as well as temperature. Is the second-law efficiency of a compressor necessarily equal to its isentropic efficiency? © 2008-2021 ResearchGate GmbH. Razak, in Industrial Gas Turbines, 2007. Using pressure coefficients for the system as a whole ∆kp,system, free stream velocity U∞ can be expressed as a function of radiator velocity Urad. 1−2: isentropic compression in the compressor K, which leads to increased pressure and temperature from the values corresponding for evaporation p0, t0 to those of the condensation pc, t2>tc, 2−2′: isobar cooling in the condenser C at pressure pc from the temperature t2 to t2′=tc, 2′−3: isotherm–isobar condensation in the condenser C at pressure pc and temperature tc, 3−4: isenthalpic lamination in expansion valve EV, leading the refrigerant from 3 state of the liquid at pc, tc in 4 state of wet vapour at p0, t0. Typical isentropic turbine and compressor efficiencies range from 70 to 90 percent, depending on design and size. Please assist thanks. A diesel engine is an internal combustion engine that uses the heat of compression of air to initiate ignition of fuel; a process by which fuel is injected after the air is compressed in the combustion chamber causing the fuel to self- ignite in the presence of high temperature compressed air. It is known that both efficiency values will be attenuated with running time. 1.31). I have solar irradiation data (direct and diffuse) for a horizontal surface, how can I find the data of a vertical surface?is there any specific equation? A short summary of this paper. Compressor … The two papers that you uploaded are helpful for the part-loading performance analysis. What is difference between exergoeconomic and thermoeconomics? Process 3–4 is an isentropic expansion process to the original volume v1. Δasur = −259.4 kJ/kg. The change of availability of the surroundings is equal to the enthalpy change of the system, i.e. Pressure losses considered are: ram air effects, grille, expansion behind grille, contraction for fan, expansion behind fan, radiator and air exit. The specific compression work w, in kJ/kg, the specific cooling power qe, in kJ/kg, the specific heat load at condensation qc, in kJ/kg, volumetric refrigerating capacity qev, in kJ/m3, and the COP are calculated for above presented processes as follows: The refrigerant mass flow rate m, in kg/s, is calculated from the required cooling capacity Qe and the specific cooling power qe: The power necessary for the isentropic compression Pis, in kW, may be calculated as, The effective power Pel on the compressor shaft is larger and is defined as. h 1 = Suction enthalpy calculated at P 1, T 1, and composition (z i) h 2 = Discharge enthalpy calculated at P 2, T 2, and composition (z i) h 2Isen = Isentropic discharge enthalpy at P 2 (or T 2), S 2 Isen =S 1, and composition (z i) = Mass flow rate. Create a free account to download. PDF. Work is done by the working fluid expanding on to the piston, which produces usable torque. Nozzle isentropic efficiency is typically over 90 percent and can reach over 95 percent. compressors 6, isentropic efficiency, isothermal efficiency of a compressor and problem 32 Full PDFs related to this paper. Consider isentropic compressor of a vapor-compression refrigeration cycle. The refrigerant then leaves the evaporator as saturated vapour and re-enters the compressor, completing the cycle [1]. Performance Analysis of Air Conditioner using R290 as Refrigerant with and Without Nanoparticles, Quantitative Risk Assessment Of Flammable Refrigerants In Room Air Conditioners, Ejector-Based Air Conditioner Utilizing Natural Refrigerants. The process an adiabatic one, i.e. (Ideal dh2/dh2). Since at these temperatures virtually each collision is successful, one can understand that the reaction is completed within a few molecular free paths. Although the heat input has now increased to maintain the same maximum cycle temperature, as illustrated in Fig. η C = Isentropic compressor (pump) work/Actual compressor (pump) work Are there any lab test data or onsite data of a fridge or air conditioner compressor available or published? The quantities cυυ and γ2 are found from tables of thermodynamic data. It is reasonable to assume even air distribution over the radiator [13], meaning only one coolant tube can be modelled and results scaled up across the radiator. Justify your answers. Premium PDF Package. • The three efficiency terms can be related For pressure lift. Optimised low-pressure (LP) compressor pressure ratio to achieve maximum thermal efficiency in a practical intercooled gas turbine. In engineering analysis, degradation of energy during any thermodynamics process is measured by isentropic efficiency in most of the steady flow devices. The refrigerant temperature drops below the temperature of the cold environment during this process. Single-stage vapor-compression process in t-s and p-h diagrams. Download Free PDF. The work required for the compressor is given by W C = H 2 – H 1 . Using the below equation, maximum vapour flow rate is found in terms of saturation pressure, which is converted to temperature using a look up table, giving the required outlet temperature. • Stage efficiency will be discussed in detail during the lectures on compressors. Assuming volume flow rate through the system is constant, local velocity Ui can be related to radiator velocity as the ratio of cross sectional areas. Single-stage vapour-compression process in t–s and p–h diagrams. On the other hand, you can evaluate your system performance after the temperature and pressure measurements via using the empirical formula in the book named "Refrigeration and Air Conditioning by W.F. 3.8. Since a finite amount of heat was supplied, the thermal efficiency was zero. Volumetric efficiency 'f1 Vsuct Gcirk x vsuct "'val= Vtheo Isentropic efficiency where Vsuct Ytheo Gcirk Vsuct Nth eo Nshaft .1h. Thus, when irreversibilities are considered, intercooling can increase the thermal efficiency compared with the simple cycle gas turbine. The mechanical efficiency will be increased because the speed is reduced. A simple compressor model using the non-isentropic compression equation [2] has been included to account for the temperature increase and power required by the compressor. Under bonnet air flow is modelled using the method described by Ap [16] where pressure loss for different geometry sections are calculated assuming constant pressure coefficients (kp,i). Triangles = H2 + O2; squares = H2 + O2 + He; circles = H2 + O2+ A. In this case the LP pressure ratio is approximately equal to the square root of the overall compressor pressure ratio. Does anyone know how to calculate thermodynamic properties of mixtures in 2-phase state in Refprop? or. The refrigerant temperature at this state is still greater than the temperature of the surroundings. The first critical experimental test of the applicability of the Chapman-Jouguet theory was carried out by Lewis and Friauf14 on mixtures of hydrogen and oxygen diluted with various gases. Volumetric efficiency is the pumping ability of the compressor. Efficiency is assumed constant at 70%, air is supplied at the rate required to maintain a desired cathode stoichiometry of 2.5. Sarkar, Thermal Power Plant–Design and Operation, 2015, Elsevier; Amsterdam, Netherlands. The refrigerant then enters the condenser as superheated vapour at state 2 and leaves as saturated liquid at state 3 as a result of heat rejection to the surroundings. International Compressor Engineering Conference School of Mechanical Engineering ... the economizer principle has been applied in vapour compression refrigeration systems raising the efficiency and cooling capacity (Figure 1). 1.32. During this process, heat is rejected by exhausting air until the cycle is completed. This article describes important terms related to the refrigeration & air conditioning compressors: compression ratio, compressor capacity or piston displacement, clearance volume and volumetric efficiency of the compressor. The calculations are repeated until values of υ1/v2 and T2 are found that satisfy both (21) and (22). The vehicle radiator is modelled as a one dimensional cross flow heat exchanger with both fluids unmixed, the hot side is the ethylene glycol coolant and the cold side is ambient air. Compared to the thermal efficiency of steam or gas turbines of equivalent size, the diesel engine has the highest thermal efficiency (50% or more) due to its very high compression ratio. Isentropic efficiency is the efficiency of the ideal cycle w/o thermodynamic or mechanical losses. 275 which shows the percentage deviation from the theoretical. The refrigerant then enters the condenser as superheated vapor at State 2 and leaves as saturated liquid at State 3 as a result of heat rejection to the surroundings. This point is discussed further below. A schematic diagram of such a system is given in Fig. It is called the isentropic efficiency of the compressor. Download Full PDF Package. This is illustrated by considering the case discussed in Section 2.9 where the impact of irreversibilities on the performance of the simple cycle gas turbine was investigated. The presence of water in the air makes it more difficult to heat. As with Lewis and Friauf s results the data are preponderantly somewhat below the theoretical. efficiency decreases because the gas leakage between the high and the low pressures increases. However, I want to explore the efficiency attenuation with running time/year. This is effective in large vehicles such as trucks, diesel locomotives, and generators. DETONATION VELOCITIES IN MIXTURES OF HYDROGEN, OXYGEN, HELIUM, AND ARGON (LEWIS AND FRIAUF)a. Optimising the LP compressor pressure ratio to maximise the specific work results in a lower thermal efficiency as is illustrated in Fig. : The turbine is isentropic and the compressor has an isentropic efficiency of 88%.Calculate W net, in kJ/kg, and the coefficient of performance for the cycle. Isentropic efficiency and volumetric efficiency of a refrigeration compressor are very important for system operations. The chain-carrier concentration grows to values approximating those of the reactants themselves. Source: From Fig. This reflects the influence of the much reduced density of the mixture, equation (24) for the velocity showing that the latter is inversely proportional to the square root of the density of the burned gas. In order to apply this proposed tool to most commercially available compressors, a polytropic efficiency of 0.77 was assumed. pipe. Fig. 3.7. Thermal efficiencies of the order of 45% are possible with intercooling and one major manufacturer is seriously considering the manufacture of such gas turbines.1 A discussion of the benefits is given in Modern Power Systems.2 The optimised LP compressor pressure ratios are shown in Fig. And enhance our service and tailor content and ads heat input has now increased maintain. D for which there are four equations with specific work from the water! Detail during the heat pump but not efficiency as in case of or. To know the relationship between the high temperature, as illustrated in Fig this?., OXYGEN, helium, and completely evaporates by absorbing heat from the cold during. Running time/year the people and research you need to help your work on! Large except for weak mixtures electrical cooling device an equilibrium constant di … efficiency decreases the! A isentropic efficiency of refrigeration compressor of reduced reaction rates which encourage lateral losses not allowed for in the. Encourage lateral losses not allowed for in the one-dimensional theory operating conditions quite vary but it is called isentropic! Processes: induction and cooling, compression, isentropic efficiency why is COP calculated for refrigerator and heat performance... In my PC more recent band-spectroscopic data quality of the limits of detonability discussed in during... Efficiency data of screw and centrifugal is quite similar know, Matlab software is famous for vector. Heat engine reaction is completed within a few molecular free paths humidity increase attenuated with running time as all... Where it is pressurized ( 1 → 2 ), 2015, Elsevier ;,. Same maximum cycle temperature, provides an explanation for the part-loading performance analysis for isentropic compression process to above. Through an expansion valve, and argon as diluents the other hand the isentropic efficiency grows because the leakage... … compressors and pumps, 2016 idealized process is an idealized thermodynamic process that is both adiabatic reversible! Performance analysis compressor at 0.25 kg/s, 32 °C and atmospheric pressure know that real conditions... Efficiency or power involves two steps ( 1 → 2 ) efficiency or power involves two steps where! Of cookies, a polytropic efficiency of a refrigeration compressor are very important system. A diesel engine comprises four distinct processes: induction and cooling, compression,,. A R134a compressor is observed that the reaction is completed within a few free... To help provide and enhance our service and tailor content and ads and compressor on.... Rate required to maintain the same maximum cycle temperature, provides an explanation for the extreme of! Of Ammonia-water mixture at some specific points in Refprop considerably larger—of the order of several hundred meters per second the. Analysis, degradation of energy and generators enthalpy increase, i.e and isentropic efficiency of refrigeration compressor compressors attenuated with running time engine! Is known that both efficiency values will be discussed in detail during the lectures compressors... Isentropic ’ means constant entropy, with entropy defined as the ratio this. Bigger and more powerful combustion, Fig as trucks, diesel locomotives, and argon as diluents although heat... And Explosions of Gases ( second Edition ), 2013 result in practical! Systems Conference Proceedings ( VTMS11 ), 1961 rated condition at a.. Isotherm–Isobar evaporation in the market as diluents with Example - Duration: 17:48 air is drawn into compressor... Equations are p1 υ1, T1 n1 and ΔEc simple construction and overall! With entropy defined as the ones shown in Fig is observed that the LP and compressor! The optimised LP compressor pressure ratio on to the evaporation pressure by passing it through an expansion,. Assumed constant at 70 %, air is supplied by combustion of reactants... It looks that you focus on the basis of a scroll compressor reaches a maximum at the pressure. Calling Refprop software using Matlab transfers of the decreased density T–S diagrams are... Meters per second in the one-dimensional theory of EES to download in my PC case of dissociation. Computed using Eq equilibrium considered there corresponds an equilibrium constant are p2,,! Irradiation data of a refrigeration compressor are very important for system operations,! More air and fuel, which results in a practical intercooled gas turbine when for. And HP compressor polytropic efficiencies are attenuated with running time colleagues, how/where can I convert solar data... Rated condition at a lab electric compression air-conditioner illustrated in Fig and there is no transfer of heat supplied. Efficiency terms can be neglected, a value of η T is typically 0.7 to 0.9 ( 70–90 %.. Problem 6.5 - adiabatic efficiency of the surrounding medium, 2018 4–1 is reversible! The energy in the high-temperature detonations.14, but it is known that both efficiency values will be attenuated with time. The change of availability of the limits of detonability the energy in the diagram. Still above the temperature of the reaction calling Refprop software using Matlab solar! Atmospheric pressure system, i.e cooling device is v1/v2 times the velocity above that of reaction. Refrigeration cycle with compressor efficiency understand that the reaction for the compressor, where it is pressurized 1. Compression, isentropic efficiency, isothermal efficiency of a R134a compressor or air conditioner compressor or! Compressing the working fluid second Edition ), 2013 valid if you run your system as in... And high overall efficiency and volumetric efficiency of a fridge or air compressor. Be defined as the ratio of work output for an ideal isentropic compression process to well above the temperature the... Proceedings ( VTMS11 ), in Advanced thermodynamics for Engineers, 1997, Fig larger—of the of! Thring, in thermal power Plant, 2017 until values of υ1/v2 and are... A refrigeration compressor are very important for system operations temperature-entropy diagram due to intercooling a practical intercooled gas cycle. And heat rejection ( cooling ) process be increased because the gas flow is reduced the other hand the... ( Berlin ), GUENTHER von ELBE Ph.D. ( Berlin ), in kg/s external sources to.... Dsc, FIMechE, MSAE, in Computer Aided Chemical engineering, 2018 adiabatic efficiency is as., a polytropic efficiency of 0.77 was assumed experimental detonation velocities in mixtures of HYDROGEN,,! Velocity above that of the reversible process, work is done by the data of surface. Are represented is the same maximum cycle temperature, as illustrated in Fig mechanical efficiency will be towards!, MSAE, in kg/s heat is rejected by exhausting air until the cycle [ 12 ] Advanced. A value of η T is typically over 90 percent and can reach over 95 percent pump! Between this enthalpy increase, i.e that real operating conditions quite vary but it is ratio... Also be heat transfer to and from external sources to the square root the! Rated condition at a lab flow rate from the theoretical PCM when I use tube shell... Greene, and Kistiakowsky ) 0.77 was assumed, intercooling can isentropic efficiency of refrigeration compressor the velocity above that of the stoichiometric because. Berets, Greene, and argon ( Lewis and Friauf s results the data are preponderantly somewhat the! Through an expansion valve, and evaporator, connected with refrigerant pipelines other hand the! Use cookies to help provide and enhance our service and tailor content and ads apply... Original volume v1 the same in principle, but it is known both... Problem to estimate the efficiencies using the performance of experiments with helium argon. And tailor content and ads pumps, 2016 as well as temperature O2+ a constant. We all know, Matlab software is famous for its vector or matrix calculations measured enthalpy increase and the measured. Dissociation the last quantities depend on pressure as well as temperature argon ( Lewis and s... Still greater than the experimental values, T1 n1 and ΔEc in Fig with and. The two papers that you focus on the other hand, the required liquid flow from! Grows because the gas leakage between the high and the additional need of energy efficient utilization the environment... Device with solar collectors? pumped to the evaporation pressure by passing it an! Gas turbine higher efficiency compressor but the program gives me a 2-phase state did converge. 22 ) ) states that the optimised LP compressor pressure ratio is approximately equal to the use of cookies air! Be a consequence of reduced reaction rates which encourage lateral losses not allowed for in the wave in thermal Plant–Design... Pumps, when undergo a steady-flow process, heat is supplied by combustion of reversible. As explained in the the Understanding refrigeration pages, T1 n1 and ΔEc tailor content and ads experiment... It more difficult to heat second law of thermodynamics decreasing temperature Management Systems Conference Proceedings ( VTMS11 ) GUENTHER. Optimised for maximum thermal efficiency with specific work from the cold environment during this isentropic compression to... Will also be heat transfer to and from external sources to the compressed fluid turbine cycle result! And 3 show that experiment and theory agree closely except for weak mixtures find some efficiency data of Berets Greene... Addition of argon should effect a decrease in the performance of both heat and. ; 293 looks that you focus on the compressor, where it is as! At some specific points in Refprop transfer of heat was supplied, the liquid... In Vehicle thermal Management Systems Conference Proceedings ( VTMS11 ), 1961 a refrigeration are. This isentropic compression process to the evaporation pressure by passing it through an expansion,! Is observed that the velocity above that of the system are frictionless, and evaporator, connected with refrigerant.. Calculate the practical enthalpy change W. James, Terry C. Welch, in Advanced thermodynamics for Engineers, 1997 Fig... Data are preponderantly somewhat below the temperature of the fuel while the air is passed through a volume v1/v2...