860029

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860029

Cylinder Pressure Data Acquisitionand Heat Release Analysis

on a Personal ComputerT. K. Hayes

and l. D. SavageUniversity of Illinois

at Urbana--ChampaignS. C. Sorenson

Technical Universityof Denmark

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ISSN 0148·7191Copyrighl1986 Society of Automotive Engineers, Inc.



860029

Cylinder Pressure Data Acquisitionand Heat Release Analysis

on a Personal ComputerT. K. Hayes

and L. D. SavageUniversity of illinois

at Urbana-ChampaignS. C. Sorenson

Technical Universityof Denmark

ABSTRACT

The availability and low price ofpersonal computers with suitable interfaceequipment has made it practical to use sucha system for cyl inder pressure data acquisition. With this objective, procedureshave been developed to measure and recordcylinder pressure on an individual crankangle basis and obtain an average cylinderpressure trace usi ng an App 1e I[ Pl uspersonal computer. These procedures as wellas methods for checking the quality ofcylinder pressure data are described. Asimplified heat release analysis techniquefor an approximate first look at the dataquality is presented. Comparisons are madebetween the result of this analysis, theKri eger-Borman heat release ana lys is wh i chuses complete chemical equilibrium. Thecomparison is made to show the suitabil ityof the simplified analysis in judging thequality of the pressure data.

One of the most useful tools in engine combustion research is the analysis of pressuretime histories for determination of the apparent rate of heat release. Some initialefforts in this line were those bySchwietzer (1)* and Austen and Lyn (2). Themost significant work was that by Kriegerand Borman (3), which coupled the heat release analysis concept to detai led chemicalequilibrium properties using a high-speeddigital computer. Their work forms thebasi s for a 1arge port ion of the heat release analysis performed with engines today.

Average pressure traces of 100 to 300consecutive engine cycles have traditionallybeen used as an input to heat release programs. This has often been performed usingFM tape recorders and digitizers which oper-

ated at reduced speeds. Developments indata acquisition technology has made it possible to el iminate the tape recorder fromthe process and acquire data directly into acomputer.

The personal computer or any computerwhich can be solely dedicated for acquiringdata, is a useful instrument for internalcombust i on eng i ne research. The output ofthe personal computer dedicated to the testcell, can be transferred to a multi-usermainframe computer for detailed engine analysis. This is attractive from an educationalviewpoint since it makes it possible to perform data acqui s it ion and graphi ca1presentation of data in a location near thetest cellon a single, inexpensive machine.

It is the purpose of this paper to describe the application of a personal computerto the acquisition of instantaneous cylinderpressure data and a simplified heat releasecalculation used to diagnose the qual ity ofthe pressure data. The results of thissimplified analysis are compared to the results obtained from the comprehensive analysis made using the Krieger-Borman methodwith complete chemical eqUilibrium. Thiswas done to jUdge the suitabil ity of thesimple heat release analysis.

EXPERIMENTAL APPARATUSThe engine used for obtaining the

cylinder pressure data was a Case ModelIBBD, 4-cyl inder, four-stroke direct injection diesel engine. Engine specificationsare given in Table 1. The engine was equipped with an AVL Model BQP5DOca water-cooled,piezoelectric pressure transducer, the surface of which was coated with RTV rubber toreduce possible effects from radiant heattransfer (4). The transducer charge wasconverted to a voltage by a Kistler Model

0148·7191/86/0224-o029S02.50Copyright 1986 Society of Automotive Engineers, Inc.



2

Table 1 Engine dimensions andoperating conditions

504 charge amplifier. The output of thisunit was routed through a simple voltageoffset circuit to ensure that the pressuresignal voltage was always positive, beforegoing to the A/D card.

The injection line pressure wasmeasured with an AVL Model 41DP500K stra i ngage pressure transducer. Thi s unit wasmounted in the injection 1ine approximately10 cm from the injection nozzle. The straingage output was run through a signal amplifier and then routed to the A/D card.

The computer used was an Apple II pluswith 48 kilobytes of internal memory and onedisc drive. In addition to the internalmemory, the computer was fitted with aSaturn System 128 ki lobyte extended memorycard. This was used to store the discoperating system software and releasedapproximately 10 kilobytes of internalmemory, allowing more room for programming,data storage, and graphics display.

The analog pressure signals weredigitized with a 16-channel InteractiveStructures Corporation Model AI-l3, 12 bitA/O converter. It occupied a backplane slotin the computer and had a trigger featurewhich allowed a single A/D read to be synchroni zed wi th an external event. The A/Ounit had a conversion time of 20 microseconds which corresponds to a maximum dataacquisition rate of 50 kHz. When binarysoftware was added to arm, read, and storethe data from the card, the maximum dataacquisition rate dropped between 16 and 17kHz with the Apple II Plus computer.

The external triggering timebase wasprovided by a B.E.I. optical shaft encoder. This unit was mounted on the frontof the crankshaft and provided a TTL signalfor every degree of engine rotation. Asecond channel on the encoder provided asingle TTL signal per encoder revolution.This was orientated with top-dead-center ofthe instrumented cyl inder to correlate thepressure data with cylinder volume.

BoreStrokeDisplacementCompression ratioSpeedBrake mean effective pressureIntake pressureCoolant temperatureOil temperature

96.4 mm104.8 mm3.0B liters16.5:11800 rpm50-600 kPa760 mm Hg82"C71 "C

DATA ACQUISITION PROGRAMA simple flowchart of the data acquisi

tion program is shown in Fig. 1. At thestart of the program, the engine volumes andvolume derivatives as functions of crankangle were read into the program from magnetic disc. This saved computational timeduring the heat release section of the program. The output file name as well as engine speed, load, and intake manifold pressure were entered at the start of the dataacquisition run.

A machine language subroutine was usedto arm, read, and store the data from theA/D card. This sUbroutine was written inmachine language in order to achieve thenecessary speed to acquire data at eachcrank angle. The computer had limited random access memory and it was not possible tostore all of the pressure records for latersorting and averaging. Consequently, themachine language sUbroutine used a procedurefor calculating an "on-the-fly" averagepressure time history. This subroutine involved several steps:

Load Vol, dVOL/daFrom Disc

VSet Output File Name

Load, Speed, and IntakeManifold Pressure

~Call Binary

Data AcquisitionProgram

iRead Data from

Memory and ReferenceCylinder Pressure

iRun SimpleHeat Release

~Graph Heat

Release Curve

~NO to Yes loutput IDisc

Figure 1 Cylinder Pressure DataAcquisition Program Flowchart.



3

1. Uniform properties throughout thecombustion chamber.

4. Constant and equal wall temperaturefor all surfaces.

2. Specific heat of air, a function oftemperature.

3. Heat transfer to the wall modeledby a uniform heat transfer coefficient.

chemi ca1of

of combustion are simulatedequivalent heat transfer

Effectsby anrate.

No dissociationspecies.

5.

6.

HEAT RELEASE ANALYSISA simple heat release model based on a

first law of thermodynamics analysis withoutchemical equilibrium (5) was used in thedata acquisition program. A short programrun time and low internal memory usagedictated this model's simplicity. It wasused to diagnose the quality of the cylinderpressure data before moving to the next datapoint; it was not for a final detailed analysis of the combustion process. The following assumptions were made in the model:

After exiting the subroutine, the binary data was read into the main program andconverted to pressures. The piezoelectricpressure transducer measures relative pressure changes and the cylinder pressure mustbe referenced to a known pressure. In thiscase the intake manifold pressure was usedas the reference value. The cylinder pressure 40 degrees before the end of the intakestroke was set equal to the intake manifoldpressure. When the cyl inder and injection1i ne pressures were read into the main program, the heat release section was run and aheat release diagram was produced. This wasused as an indication of the qual ity of thepressure data.

At the same time, maximum cylinderpressure, rate of pressure ri se, and thei rlocations were determined. The start of injection was determined from the 1ine pressure data. The normally accepted procedureis to use needle 1ift measurements to determine the start of injection, but thisproved to be impractical due to instrumentation problems with the particular injectorsused. After examining the heat releasecurve, a decision was made to store thepressure data permanent lyon magnet i c di scor to retake the data at the same testpoi nt. The execut ion time of the programfrom the start of the data run to the outputof the heat release curve was approximatelytwo minutes.

4. Replace the new sum in the appropriate memory location.

2. Recall the stored sum of the pressures for that given crank angle.

3. Add the current pressure to theprevious sum.

There were two 1imitat ions encounteredin this procedure. The first was the timerequired for the AID card to make themeasurement. The second limitation encountered was the amount of time requ iredfor the computer to execute the programsteps for the above procedure or the software limitation. For the current application, the total time required to acquire andprocess the measurement and get ready forthe next measurement 1imited the dataacqui sition procedure to a speed of approximate ly 2000 rpm for the measurement of onedata channel at intervals of one crank angledegree. Should the engine exceed the speeddefined by these limitations, the resultswould be obvious since the data would beacquired at every other crank angle. Thespeed 1imitations are dependent on theparticular type of computer and AID converter used.

It was possible to achieve further increases in maximum engine speed using a procedure by which measurements were taken forone cycle and stored but not averaged untila complete engine cycle had been measured.Oata acquisition was then interrupted forthe next cycle while the results from thelast cycle were added to the stored, summedresults from all of the previous cycles.With this procedure, the limiting enginespeed could be increased to approximately2700 rpm.

This results in an increase in speedfor the acquisition process since it reducesthe number of calculations performed beforethe computer is ready to receive the nextpressure value. It does have the disadvantage that the results are not taken forconsecutive cycles. If the engine isstable, this should not present a statistical problem if cyclic variations are to bedistributed according to a normal distribution.

5. Advance the crank angle counter inthe program.

6. Repeat the procedure for the nextcrank angle.

7. At the end of the entire dataacquisition process, divide each ofthe sums by the number of cycles.

1. Measure the pressure when triggeredby the signal from the crank angletransducer.



4

1. Engine rpm,

2. An experimental cyl i nder pressurehistory, and

Under these assumpt ions, the fi rst 1awof thermodynami cs can be solved for the apparent heat release rate:

Q _V_ dP + -1.- P dV _ Q (1)app = y - 1 de y - 1 de w

3. An estimate of the initial mass inthe combustion chamber.

The initial mass in the chamber was calculated using the ideal gas law with thetemperature of the air at 350 K at the closing of the intake valve. This assumptionwas used for all engine loads.

(4)

0.488256T2

1 x 106

0.005701327T4j

R1 x 1012

{3 04473 + 1.33805T• 1000

for T > 1000 K

+ 0.0855475T3

1 x 109

1. Engine RPM.

2. A homogeneous mixture of air andcombustion products.

3. 8urning takes place incrementallyand was modeled as a uniform heataddition.

1. Thermodynamic equilibrium at eachcrank angle.

where T = temperature (OK) and R = universalgas constant (KJ/Kmol).

KRIEGER AND 80RMAN HEAT RELEASE ANALYSISI~ order to determine its suitability,

the Slmple Heat Release Analysis was Compared to a more comprehensive model based onthe Krieger and 80rman Method (3). Thisprogram was run on a CDC CY8ER 175 computer. The following assumpt ions were usedin this model:

2. An experimental cylinder pressurehistory.

3. Combust ion chamber surface temperature.

4. All of the fuel was convertei toproducts of combustion.

5. Heat transfer to the combustionchamber walls was modeled by a uniform heat transfer coefficient.

6. Constant and steady combustionchamber wall temperatures.

This heat release program, which was~ritten by Faletti (8) had the option of uslng either the Woschni or the EichelbergHeat Transfer Correlations. The EichelbergCorrelation was chosen in order to make acomparison with the simple heat release output.

This program requires several inputsprior to execution:

(3)

(2)

} R

( _ CP _ )C - RP

y

1.33736T + 3.29421T2

1000 1 x 106

1.91142T3 + 0.275462T4

1 x 109 1 x 1012

{3.6359 -

for T < 1000 K

where P = cylinder pressure, Qapp = apparentheat transfer (release) rate, Qw = heattransfer to the gas from the wall, V =cylinder volume, y = specific heat ratio,and e = crank angle degree.

This equation can be solved usingmeasured cylinder pressure and rate of pressure change calculated from the experimentaldata along with cylinder volume and rate ofchange of cylinder volume as calculated fromthe slider crank equation. The equationsfor the specific heats are given below (7):

The Eichelberg correlation was used tomodel the heat transfer to the combustionchamber surface (6). The combustion chamberwas assumed to be 450°C and the heat transfer area was calculated assuming a cylindrical disc for the combustion chamber. Thefollowing inputs were required for thesimple heat release model:

4. Initial mass and composition in thecombustion chamber.



5

The mass burning rate curves in Fig. 2for a BMEP of 50 KPa show that both modelsindicate the injection and vaporization ofthe Diesel fuel as shown by the dip in thecurve before ·the start of combustion. Bothmodels predict the same point for the startof combustion. During the premixed phase ofcombustion the simple model indicates highermass burning rates by 29 percent, and thatthis phase of combustion OCCUrs for a longerperiod of time. The simple model underpredicts the Krieger and Borman model duringthe diffusion controlled combustion.

The fraction of mass burned curves fora BMEP of 50 kPa, Fig. 3 indicates that thesimple model predicts a higher fraction ofthe mass burned during premixed combustion. The lower mass burning rates observedduring the diffusion burn in Fig. 2 correspond to the fact that the simple modelpredicts only 90 percent of the massburns.

360. 380. 400.Cronk Angle (Deg.)

Bmep= 50 Kpa-- Simple lAIr- - Krieger 6, Barmen

\\j

I ~~-

-""""'20

0.00

-,Oe:340.

0.10

0.08

0.04

0.02

o.eo0.18

O.HI

0.14

0.12

1. The Krieger and Borman model usedthe initial cylinder mass obtainedfrom a Diesel engine simulation.The simple model used a rough estimate for the initial mass.

RESULTSThe major differences between the two

heat-release models were:

The combustion chamber surface temperature was estimated to be 450°C for allcases. This was the value used in thesimple analysis. The initial mass and composition in the cylinder was found using acomplete Diesel simulation which includedintake and exhaust effects (9).

The computer program calculated theequil i bri um thermodynami c properti es of themixture in the combustion chamber at eachcrank angle. This program differed from theoriginal by Krieger and Borman in that theequilibrium composition of combustionproducts were calculated with a subroutinedeveloped by Strehlow (10) and the thermodynamic properties of the mixtures were calculated with a subroutine developed bySavage (11). These subroutines were usedinstead of the curve fits developed byKrieger, Borman and Dlikara (12).

2. The Kri eger and Borman model i ncludes dissociation and completechemistry while the simple modelused air as the working fluid.

Both models had the following points incommon:

1.

2.

The Eichelberg Heat Transfer Correlation.

450°C combustion chamber surfacetemperature.

Figure 2 Comparison of Normalized MassBurning Rates at a BMEP of50 kPa. The Simple Heat ReleaseModel using an Assumed InitialMass.

~ 0.4

Bmep= 50 Kpo-- Slmplll I Atr- - Krloger 6' Borman

Comparison of the Fraction ofMass Burned Curves at a BMEP of50 kPa. An Assumed Initial Masswas used in the Simple HeatRelease Model.

J0.0.L,----:~---~---__::::,_--_;;!.340, 3150. 360. 400. 420.

Crank Angle (Deg.)

1.0 r----~----,----~:_:::-=--.......,----

Figure 3

c.2b o.eo'-u..

1$c5 0.8enNoting these points a comparison of

both heat re1ease models was made to determine the validity of the simple method asa tool to evaluate the quality of theexperimental pressure data.

Figures 2 through 7 show the comparisonof the heat release models. The apparentheat release rate was normalized by dividingit by the mass of fuel injected per cycleand the lower heating value of the fuel. Itis plotted in Figs. 2, 4, and 6 as anormalized mass burning rate. The massburning rate curves were numerically integrated using the trapezoidal rule to produce the fraction of mass burned curvesshown in Figs. 3, 5, and 7.

3. The same experimental cylinderpressure data.



6

0.20 ,----~----,_---_r---......,

0.18

0.16

0.14

0,12

0.10

At a BMEP of 600 kPa, Fig. 6, bothmodels again show fuel vaporization and thesame start of combustion. The simple modelpredicts 47 percent higher mass burningrates and a longer duration for premixedcombustion. The simple model predictshigher initial burning rates during the diffusion controlled combustion but the twomodels come in closer agreement towards theend of the diffusion combustion. Thesefacts are also shown in Fig. 7 where it isevident that the simple model over predictsthe heat released since the fraction of massburned approaches one well before combustionis complete.

The initial mass in the cylinder obtained from the engine simulation in theKrieger and Borman analysis was used in thesimple analysis. This was done to determinethe effect of the rough estimate of the initial mass on the output of the simplemethod. Figures Band 9 show the results ofchanging the initial mass.

0.08

~ 0,05 \

i 0.0' ....... '"6 0.02 ) \....: -..!.......~ ~,...",--.~o 0.00 1=,...,."---- _'::::~~=~""'=--l

-.01!.'-;;------,c:!:=----=---~=_--__7.!340. 360. 380. 400. 420.

Cronk Angle (Deg.)

«uo....

Bmep= 300 Kpo-- Simple /p.!r- - Krlcgor 6: Borman

0.08

0.10

0.04

0.02

0.20r----~----,_---_r---___,

0.18

0.115

0.14

0.12 1\

1\

\\~

I -----::::::="""=;e.,.=--i0.00 A=--==.-'-- ----.01! !::---~;----,;t;---:;;;;;------,;

340. 360. 380. 400. 420.Cronk Angle (Deg.)

Figure 4, the mass burning rate for aBMEP of 300 kPa indicates both models predict the injection and vaporization of theOiesel fuel, as well as the same start ofcombustion. The simple model predicts 44percent hi gher burni ng rates, and a longerduration for premixed combustion. Bothmodels predict equal mass burning rates fordiffusion controlled combustion.

At 300 kPa, the fraction of mass burnedcurves, Fig. 5, the simple model predicts ahigher percentage of the mass consumed inthe premix phase. The simple model greatlyover predicts the heat released as the shownby the fact that the fraction of mass burnedcurve reaches a value of one before combustion is complete.



1.0 1.0 ----0 --- -0 ------'" --- '" --c ./ c ./....0.8 ....

/;;) / ;;) 0.8co co /III / IIIIII 0,_ / III 0.6 - /0 0::;; / ::;; /"" 0,4 ( "" 0.' I0 0

c r c '/0 Bmep= 300 Kpo .2 Bmep= 600 Kpo+= o,e r0 ¥

~ o.e-- SImp!" I Air 0 -- SImple I AIr0 - - Krloger 6 Borman 0 - - Krloger &. Borman.... .... 1"- 0,0 "- 0.0

340. 360. 380. 400. 420. 340. 360. 380. 400. 420.

Crank Angle (Deg.) Crank Angle (Deg,)

Figure 5 Comparison of the Fraction of Figure 7 Comparison of the Fraction ofMass Burned Curves at a BMEP of Mass Burned Curves at a BMEP of300 kPa. An Assumed Initial Mass 600 kPa. An Assumed Initial Masswas used in the Simple Heat was used in the Simple HeatRelease Model. Re 1ease Mode 1.



o.eo 1.0

Bmep= 50 Kpa "0~ 0.18 <l)

0> -- Simplo lAIr C<l) 0.1lS "-a - - Krlogor 6: Bormen " 0.8

" 0.14 Cllrl~

0.12 UlUl 0.'« Ii 0

0 0.10 ::;;a 0.08 I" "-~ 0 0,4

;,; 0.06 l::;; 0.04C

" L 0

::;; } :;:: OJ!0.02 0~ 0a 0.00 :::-- . "-

-.02u..

0.0340. 3150. 380. 400. 420. 340.

Crank Angle (Oeg,)

(a)

a.eo 1.0

0.18 Bmep= 300 Kpa "0~

<l)

0> -- Simplo lAIr C<l) O.1e - - Krlogllr 6: Borman "- 0.8a "" 0.14 Cllrl~ O.1e Ul

«Ul 0.8

0.10 0U

1\::;;

a 0.08" "-~ 0.06 0 0,4

::;; 0.04 \. C

" I) 0

::;; 0.02 Ii:;:: 0.'

~0

a 0.000"-

-.oe u..0.0

340. 3150. 380. 400. 420. 340.Crank Angle (Deg,)

(b)

Bmep= 50 Kpa-- Simplo I Air- - KrlOllor & Barmen

3150. 380. 400. 420.Crank Angle (Oeg.)

(a)

Bmep= 300 Kpa-- Simplo I Air- - KrlOllor 6: Borman

3lS0. 380. 400. 420.Crank Angle (Oeg.)

(b)

7

Bmep= 600 Kpa-- Simple lAir- - Krlogllr 6 Borman

.

11.j

} l

- - . - -

o.eo0.16

0.16

0.14

0.12

0.10

0.08

0.06

0.04

0.02

0.00

-.02340. 3150. 380. 400.

Crank Angle (Oeg.)

(e)

420.

1.0 ..-,;"0 --='" -c /:"- 0.8 /,"Cll hUl ;;Ul 0.'0::;; ;;"- 0.' I'0

c ,1.2 Bmep= 600 Kpa~ 0.'0 -- Slmplll I Air0'- - - Krloger & Barmonu..

0.0340. 360. a80. 400. 420.

Crank Angle (Oeg.)

(e)

Figure 8 Comparison of Normalized MassBurning Rates at Various BMEPs.Both Heat Release Models usingthe Initial Mass from an EngineSimulation.

Figure g Comparison of the Fraction ofMass Burned Curves at VariousBMEPs. Both Heat Release Modelsusing the Initial Mass from anEngine Simulation.



The mass burning rate curves, Figs.8a,b,c, shOl' very good qual itative andquantitative agreement between themethods. At all loads, the Krieger andBorman method pred i cts slightly hi gher massburning rates during the initial phase ofthe premixed combustion. At all loads, bothmethods predict the same burning rates during the diffusion controlled combustion.

The fraction of mass burned curves,Figs. 9a,b,c, show that the Krieger andBorman method predicts a higher fraction ofthe mass burned during premixed combustion. The fraction of mass curves from thesimple analysis do not vary more than 4 percent from the Krieger and Borman results.

DISCUSS IONThe results show that qualitatively the

simple model agrees well with the more comprehensive Krieger and Borman model. Thesimple model over predicts the heat releaserates for premixed combustion at all loads,and at loads of 300 and 600 kPa over predicted the total energy released.

The simple model does indicate the correct start of combustion as well as the effects of fuel vaporization. It also showsthe progression from mainly premixed combustion at low loads to a combination of premixed and diffusion controlled combustion athigh loads as expected with a Dieselengine.

The major difference between the simpleand Krieger and Borman models aside fromchemistry and dissociation was the estimateof the initial mass in the system. A roughestimate was used instead of a engine simulation in order to reduce the program running time. Judging from the results obtained by substituting the initial mass fromthe engine simulation into the simple analysis, a better method for predicting the initial mass in the system should be investigated.

CONCLUSIONSThe results presented indicate that a

personal computer can be used to acquiresingle degree pressure data from low speedDiesel engines. The simple heat release wasshown to be a good diagnostic indicator forthe quality of the cylinder pressure data.The heat release model appears to be as goodan indicator of cylinder pressure errors asthe logarithmic pressure-volume diagram proposed by Lancaster (4). This computer system with its apparent heat release analysisdiagnostic can be used to obtain a significant amount of data at a relatively lowprice. In summary:

1. Procedures have been developed toacquire cycle averaged cylinderpressure, or other cyclic enginemeasurements on a personal computerof a small size.

2. A simplified heat release analysisfor diesel engines using the temperature dependent specific heatsof air has been shown to be an adequate method of evaluating thequality of the cylinder pressuredata.

3. The heat release analysis is sensitive to the values of initialcylinder mass and residual fraction. Improved methods forestimating these quantities need tobe developed. These methods mustbe in a form compatible with thecapabi 1iti es of the personal computer to be used ina mOrequantitative manner.

ACKNOWLEDGMENTSThis work was supported by the Illinois

Department of Energy and Natural Re-sources.

REFERENCES

1. SChwietzer, P., "The Tangent Method ofAnalysis of Indicator Cards of InternalCombustion Engines," Bulletin No. 35,Penn State Univ., Sept. 1926, as referenced in Obert, E. F., Internal Combustion Engines, Harper and Row Publishers,New York, 1973.

2. Austen, A. E. W., and W. 1. Lyn, "TheAppl ication of Heat Release Analysis toEngine Combustion StUdy," CIMAC, p.1067, 1962.

3. Krieger, R. 8., and G. L. Borman, "TheComputation of Apparent Heat Release forInternal Combustion Engines," ASME Paper66-WA-DGP-4, 1966.

4. Lancaster, D. R., R. B. Krieger, and J.H. Li eni sch, "Measurement and Analys i sof En9ine Pressure Data," SAE Transactions, Vol. 84, p. 155, 1975, Paper750026.

5. Sorenson, S. C., "Simple ComputerSimulations for Internal CombustionEngine Instruction," InternationalJournal of Mechanical Engineering Education, Vol. 9, p. 237, 1981.

6. Eichelberg, G., "Some New Investigationson Old Combustion Engine Problems,"Engineering, Vol. 148, p. 463, 1939.



7.

12. C. Olikara, and G. L. Borman, "A Computer Program for Calculating Propertiesof Equi 1ibrium Combustion Products withSome Applications to I.C. Engines," SAEPaoer 750468. 1975.

11. Savage, L. 0., Jr., "PROPSI-A Subprogramfor the Calculation of Thermodynamic andTransport Properties of Common GaseousMixtures," Report UILU ENG 77 401, University of Illinois at Urbana-Champaign,Sept. 1977.

Zucrow, M. J., and J. D. Hoffman, .GasDynamics, Vol. 1, John Wiley and Sons,New York, 1976.

8. Faletti, J. J., S. C. Sorenson, and C.E. Goering, "Energy Release Rates fromHybrid Fuels," Transactions of the ASAE,Vol. 27, p. 322, 1984.

9. Faletti, J., "Energy Release Rates ofHybrid Fuels in a Diesel Engine," M.S.thesis, Department of Mechanical and Industrial Engineering, Uni ..ersity ofIllinois at Urbana-Champaign, May 1983.

10. Strehlow, Roger A.,amentals, McGraw-HillYork, 1984.

Combustion FundBook Co. , New

9



Th1I paper iJ aubJect to tcYidon, Statementl and opinion. ad.vanced in papen or d1Jculllon are the author'. and are hisrespondblllty. not SAE'.; however, the paper hu been editedby SAE tor uniform JtYUns and fonnat. D1Icullloa wDl beprinted with the pape: itIt II pub11lhcd in SAB Tramaetlons.Forpemtlu1on to pUblbh th!Ipeper in fun or In put, contacttho SAB PubUcationJ DlviIlon,

PmoDJ wbblnl to IUbmtt papen 10 be COftIIdered lor proaentlt!on or pubUcatlon throuab SA! IbouJdICad 1M JUlUoICdpt or • 300 wend ab.tract 01 a propoted DlIIlWCI'Ipt to:_lIlY. Enalnecrlna AC1Mty Board. BAE.

_ pap booklet.



860029

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