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Vol. 9, No. 30, January, 2014, 113·122

1 HEORETICAL INVESTIGATION OF THE PERFORMANCE OF DIESELENGINE FUELED BY BIODIESEL

S. M. A. Ibrahim!, K. A. Abed1, M. El Bayoumyl and M. S.Gad11Department of MechaniCal Engineering,Al- Azahar University, Nasr City, Egypt2Department of Mechanical Engineering, National Research Center, Dokki, Egypt

ABSTRACTA q~asi dimensional two zone compression ignition engine cycle model is used to predict theC) c1e'perforinance of a diesel engine for the cases of using diesel fuel, B5, B20, B40, B70 andB i00; The apparent fuel burning rate could be expressed as the sum of two components, one[f.; Iating 't6 premixed and the ~ther to diffusion burning. Governing equations of the mathematicalm:)del mainly consist of first order differential equations derived for cylinder pressure,te nperature, cumulative work done, specific fuel consumption and thermal efficiency. Ac(mputer code for the cycle model has been prepared by Matlab to perform numericalc, lculations at different engine loads for verification of the model. An experimental investigationh, s been carried out on a diesel engine fuelled withB20, BIOOand diesel fuels. Itwas observedthat there is agood agreement betw~en simulated and experimental results, these results indicatethat the a.ssul11pti,onsof the model are reasonable. It is shown that specific fuel consumptionv,··!uesfor diesef: biodiesel blends (B20, B40, B70 and B100) were slightly higher them dieselft,el by about from 2.5% to .13%respectively, the thermal efficiency for biodiesel-diesel blendsU '20, B40., B70 and B 100) were lower than that of diesel fuel by about from 0.05% to 0.22%rnpectively.

1\ EYWORDS: Jatropha oil, Biodiesel, Specific fuel consumption, Thermal efficiency,.' Simulation.

1 INTRODUCTION "C )mputer ~imulation has contributed enormously towards new evaluation in the field of internai ) ;,C( 1mbustion engines. Mathematical tools have become very popular in recent years owing to theC( iI1tinuously increasing improvement in computational power. Diesel engine simulation modelsrlduce the number of experiments, decrease complexity and computer system requirements.( l}mputer simulations reduce time and costs for the development of new engines. ComputerSJ mulations of in~ernal combustion engine cycles are desirable because of the aid they provide ind.!sign stu'qies,' predicting trends, serving as diagnostic tools, giving more data, less time and costtl an are normally obtainable from experiments, and helping to understand the complex process thllt(I ;cur in the combustion chatnb,yr" Computer models of engine processes are valuable tools foranalyzing eng,ine performance, exha).,lstemissions prediction and allow exploration of many engined':sign alternatives in an inexpensive fashion, [1]. .

113

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THEORETICAL INVESTIGATION OF THE PERFORMANCE OF DIESEL ENGINE FUELED BY BIODIESEL

M'1thematical engine simulation models are divided into two main groups. The first is fluid dynamicsbe,sedmodels and the second is thermodynamics based models. The former models are called multid inensional models which are based on the conservation of mass, and energy at any location withintll : engirie'"cylinder. The latter models are based on the thermodynamic analysis of the cylinderc( ntetl,tsduring the engine, qptfrating, cycle ..piesel engine. simulation models can be classified intoth 'ee ((~t~gories, zero dimerisidha1,'single:.zo,il,~ piodels; ,qiIasi dimensional, multi zone :models andm dtidimensional models. Zero dimensional; single zone ~odeWassume that the cylinder~;charge isLIt iform in both composition and temperature, at all time 'durin.g the cycle. It has,beenshown thatc;:,(ibrated and validated single zone models are capable of predicting engine perf0~.p~~ ~d fuelet,lnomy accurately and with high computational efficiency. However, single zone,rhodeIg:6lifinot beL1' ed to account for fuel spray evolution and spatial variation in mixture composition andte nperature, which are essential to predict exhaust emissions. On the other hand, multidimensionalm )dels, like KIVA resolve the space the cylinder on afine grid, thus providing a formidable amounto I special information. , i' , . 'I, '. " :,' '" . ,\., ;' ,: .

A ; an intermediate step between zero dimenSional and multi dimensional models, quasi dimensional,m llti zone models can be effectively used to model diesel engine combustion systems. The quasid i nensional models combine ;some of the advantages of zero dimensional models and multid i nensional models. They solve mass, energy equations, bui do not explicitly solve the momentume( uation. These models can provide the spatial information requiredito predict emission products andre luire significantly less computirig resources compared to multi dimensional models. Quasid i nensional combustion modeling could be considered an active area of research, [2].o fer the years, numerous models have been developed to predict engine combustion )-\'i*m,ore than01 e zone, Within those multi zone spray combustion models, the level of ,detail, 'fidelity and,v( lidation embedded in individual sub modelS have varied considerably. Furthermore, only;a subset"oJ these models has aimed at predicting emissions, especially,NO apd soot. A number 'of multi zoneUJ' )dels have tracked the mixing of gaseous jets :with air and subs~quel1t combustion, withoutccnsidering the fuel spray dYn.aJnicS,[3]'. .

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,2; MATHEMATICAL MODE;L FORMULATION' .' . :,,", :'Jn·the present· work;-,a,quasi dimensiona] two. zone thermodyn?mic. model i,8,c}j.'q~el1td: ~iri1ulate,Jour stroke cycles; (int~ke, cOl11pression,expansion, and exbaust). 9rcompre,~,si9n, ~gnition engine,,fl):::lledwith various types of alternative fuels,;such as diesel,: bi:oqies~La:iid their blends. ThisHodel predicts engiri~' perform¥n'ce paramete'rs;'The combustion wodel was chosen to give at'nsonable aCCWc;lyYwith fast computation. The,;unbOmed 'l11ixtU1;e,forcompression,'ignitioner gine during intake and compressioll strokes 'consists of air, and previoUSly burned gases. Thec! mposition of the unburned mixture does not change significantly during intake andc(,mpression strokes. It is sufficiently accurate to assume the composition is frozen [3, 4J.T Ie combustion products or burned mixture gases are close to thermodynamic equilibrium duringth; combustion process and much of the expansion process. In this model, the cylinder charge isa~sumed to be uniform in both temperature 'and;composition ..The burned gases are considered tob! in chemical equilibrium whereas the unburned gases are assumed to be frozen. The firsUaw ofth::rmodynamics, equation of state, conservation of mass and volume are applied to the unburned,ai;d burned gases. A system of first order ordinary differential equations can be oi;>tained,fo~ thepl,essure, mass, volume. and temperature of the' unburned and burned gases. The first law ofthertnodynami~s is'.used to' c~dculate the pressure, "heat release rate and the mass fraction ofb i (med gases as a 'function oJ~tank angle, [5].' . , , " ,

;,;':,lJ this approach the comb4stion models, such as Wiebe model, Watson model and Whitbhbuse;\A'ay model, ,are' .~valuated ''based' on the comparison of the computational results 'with

"i' e; ,periroental da~a ;:I.S ,tp check, reliabi lhy and feasibility of mode1.sin predicting working process. o· d'i~sel engit:Ie.TfW comparison shows .'that above mentioned three models can be used for the

" engineering p,uxpqs,etopredict performance characteristics of the engines operated with diesel.... ,.' . . . - .l~rI

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THEORETICAL INVESTIGA nON OF THE PERFORMANCE OF DIESEL ENGINE FUELED BY BIODIESEL) /~

'] 1e heat addition for compre~sion ignition engine may be a function of crank angle. Watson et alp oposed that the apparent ftiel burning rate could be expressed as the sum of two components,o Ie relating to premixed and the other t6 diffusion burning.Among these models, the predictingn suits with Watson model agree best with the experimental data, so Watson model is sekcted.\l' atson model consists of two functions which are superimposed. The first function simulate~ thep emixed combustion and the second simulates the diffusion combustion. A weighting factor P isu ;ed to determine how much emphasis is given to each of the function, [6, 7, 8].

dmb = dmp + dmd (1)dB dB dB

(2) , \

.,'"

(3)

(4)

(5)

(6)

(7)

(8)

(9)

(10)

(11)

m ¢0.35r = _____!:_ = 1- 0.875 0.375m" ID

(2 = 5000

T _ 0 79K 0.25j '4 -. 3

Where:

m mass of fuel - air mixture in kg,mb fuel mass burned in kg,mp fuel mass b,~rned in premixed phase in kg,md fuel mass burned in diffusion phase in kg,P Weighting factor,cD Fuel - air equivalence ratio,ID ;Ignitidn eelay in millisecond,N Engine speed in rpm, . .KJ ,K2,K3, and K4 shape factors for premixed and diffusion burning phases,

115 lAVES, 9, 30, 2014

THEORETICAL INVESTIGATION OF THE PERFORMANCE OF DIESEL ENGINE FUELED BY BIODIESEL

Sign start angle of heat release (combustion start angle),~S the duration of heat release (combustion duration from Xb=Oto Xb=l) is

given by 100 Crank Angle as a datum value which needs to be large"; i, enough to complete combustion arid';i',; 'Xb mass fraction burned.In the present model, the engine fuelled with some fuels such as diesel, biodiesel, mixture of

diesel and biodiesel. The molecular formula used for diesel is taken as CIOH20,whereas forjatropha biodiesel, it is taken as C.18H3402. . .

2.1 Heat TransferHeat transfer has become inevitable in any internal combustion engine so as to maintaincylinder walls, cylinder heads and pistons at secure in service temperatures. Heat is transferredfrom or to the working fluid during every part of each cycle. The primaryheat transfer from the cylinder gases to the wall is convection and only 5% for radiation. Theheat transfer is giv,en by the following equation, [9, 10].

Qht = hA(T - Tw)+ et;(T4 - Tw4) (12)

Where:h the heat transfer coefficient in W/m2.K,A the combustion chamber surface area in m2,Tw the wall temperature in K,E emissivity (E =0.69 W/m2.K4) andS Stefan Boltzman constant =5.67xlO"'-8 W/m2.K4•

Woschni accounts for the increase in gas velocity in the cylinder during combustion. Theaverage cylinder gas velocity U for a four stroke engine without swirl determined by Woschniis, [11]:The heat transfer coefficient given by Woschni is: ..

h(B) = 3.2f(b-o.2)(pO,8)(T-0.5S)((CIUp +C2(;~ )(P- Pm))0.8) (13)r r

the cylinder bore in m,the cylinder pressure in atm,the cylinder temperature in Kelvin,the displacement volume in m3,the motoring pressure in atm,mean piston speed in mlsec,the average cylinder gas velocity in m/sec,engine compression ratio,the atmospheric pressure (Pat =1 atm),are constants, compression (CJ=2.28, C2=0),induction ~nd exhaust (C1=6.18, C2=O) andcombustion and expansion (Cj=2.28,C2=O ..00324).the reference temperature, pressure, ~ndvolume respectively that we takethem the initial conditions for compression stroke.~:. :'. . .

] .2 Ign ition Delay . . .i' i .

i;nition delay is the time period between the star(Qf i~J~ction of fuel (tinj) and the start oflombustion (tign).The start of injection is usually taken ,as the tiine when the injeCtor needle lifts( ff its seat. It is a complicated function of mixture temperature, pressure, equivalence ratio andt le fuel properties. It is best defined from the change in slope of the heat release rate versus time

Where:bPTVdPmupu

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THEORETICAL INVESTIGA nON OF THE PERFORMANCE OF DIESEL ENGINE FUELED BY BIODIESEL

cur" e which occurs at ignition. The Wolfer's empirical relation is used to determine the ignitiondeja y, [11, 12].I') =AP-nexp (EI RT) " (14)

Nhere:

IJ . the ignition delay in milli second,

r"apparent activation energy for the fuel autoignition process, Joule

R universal gas constant, 287 J/kg.K,P the gas pressure in atm,1 the gas temperature in K, andf\ ,n are constants depend on the fuel, injection and air characteristics.

3 FORMULATION OF THE MODELTie differential first law of thermodynamics for this model for a small crank angle change de]':

dQ-dYf( = dUThe ideal gas equation of state as:

PV = mRgasTWhere:

(15)

(16)

Rgas the gas constant (Rgas=0.287 kJ/kg.K),P the cylinder pressure in Pa,V the cylinder volume in m3 andT the mean gas temperature in Kelvin. I

T Ie total volume of the engine cylinder and the rate of its change as follow:V V .

V=(_d )+(~)(R+l-cos(B)-(R2-(sin(B»)2)O.5) (17)r -1 2

dV = (Vd(sin(B)))(l + (cos(B»(R2 ~ (sin(B)))-O.5)dB 2

R = 21L

(18)

(19)

where:Vd the swept volume of the engine in cubic meter,L the engine stroke in meter,b ) , the engine bore in meter.I the engine connecting rod length in meter andR the ratio of connecting rod length to cral1kradius.

dP = (k-l)(CdQ)_C!!:i)(T_T »~(kP)(dV)de V de 6N W V de (20)

117 , JAUES, 9, 30, 2014

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THEORETICAL INVESTIGATION OF THE PERFORMANCE OF DIESEL ENGINE FUELED BY BIODIESEL

dT ~ ('!_)( dP )'+ (T)(dV) " "de P de V de

iolving the above equations with appropriate input data enablelressure, temperature, specific fuel consumption and thermal.

(21) I.t

for determination of the'

4, NUMERICAL & COMPUTATIONAL METHODTI e computer code is developed to be suitable for any hydrocarbon fuel versus diesel,bi )diesel and its blends. The engine geometrical parameters, molecular weight of gaseous .pr )ducts and the various constants used in the modeling are defined. The input parameters used inth : modeling are the compression ratio, relative air-fuel ratio and the molecular formula of thefu ~l.From the geometry of the engine, the combustion chamber volume at'every degree crankangle is calculated. Wolfer's relation is used to determine the ignition delay of gaseous mixtures.H 'at release due to combustion of the mixture is calculated using Woschni heat tr~nsferc(.rrelation.. The pressure and temperature of the gases are calculated for' every degree' crank .aT'gle. The outputs of the modeling program are instantaneous pressure, temperature, volume and'th ~performance parameters that include specific fuel consumption and thermal efficiency; ,['13,-l/~, 15]. l,.-'

A set of linear equations numerically, these are:1- Energy equation and mass balance.2- First law of thermodynamics for each zone (unburned and burned).3- Equation of state.4- Woschni heat transfer correlation.The computational method predicts the following parameters:1- Pressure, temperature -and cumulative work done in the cylinder at every degree crank

angle for biodiesel- diesel blends.2- Specific fuel consumption -and thermal efficiency at engine different loads for biodiesel-

diesel blends.5, RESULTS AND DISCUSSION5.1. Effect of Fuel blend on Cylinder Pressure .TI'e simulation results of blends like B20, B40, B70 and B100 show lower peak pressure thanD 00 by about from 1.5% to 7% respectively as shown in Fig.t. This is due to Jatropha biodieselh3;; higher viscosity and volatility causing poor atomization, slow heat release 'rate, mixturepr ~paration and formation. The' peak cylinder pressures are low with biodiesel' blends inc( mparison to diesel since the hea~ng value of biodiesel is lower than that of diesel resulting in10 ver heat release.

,~~~ ..~:~.-:..:.-...-•••.•••-••. -,' 'mm'm' ••••••.._•.", __ .".,__•••••'_m. •__..•,. "., ••••,••••.,••••,.,•••••••,••••.•••.••-"", .•-•.•"-----, ••..•...•.•,.-", ...•...-•.,.•..-.•-.•,. I

-0100

.... --·1320

----B40

- - 1370

- . -8100

-100 o 100 200-2.00

Crank ~ng'e, Degree

Fig.1 Comparison of cylinder pressure for biodiesel blends, and diesel fuelsat full load and r$ted speed

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THEORETICAL INVESTIGATION OF THE PERFORMANCE OF DIESEL ENGINE FUELED BY BIODIESEL

5. l Effect of Fuel blend on Cylinder Temperature1'le simulation results of blends like B20, B40, B70 and B 100 sho\\;,)ower peak temperature thanD i00 by about from 1.5% to 7% respectively as shown in Fig.2. The peak cylinder temperature isIe N with biodiesel blends in comparison to diesel since the heating value of biodiesel is lowertilm that of~.~.~L.~tilliP._gi~l2_VY~..!.!~l~.~~~_.----""'''.-'''''''-- ..,,-.-----"'''--.-""---,--'" "''''I

"'"i·····.a~~E~....~ -.- ~~.--..~.•......-.- ..5~ ,.:= -, =;~;:;;;;__ ~'_40 ..

"",.,""""""'" ""', , , ".," 20u.. + '''''',c,,'''''''''' ",,,,,,,,,,,,,,,,,,,,,,,.,,,,.,,,,,,.,,,,. "" """"""""""."""""""~",,, ..

-DI00

.; .. ,.,.,B20

----B40

- - 870

- . -·B100......... 1.. . . """"""".{)".".".L."

o 1.00

............... \...., .. ...... ; ,,, ...•........ 1

-200 -100..Crank Angle. Oegree

. \ ,:

Fig.2 Comparison of cylinder temperature for biodiesel blends and diesel fuels'at full load and rated speed

.5,3 Effect of Fuel blend on cumulative work doneF gure.3 shows cumulative work done against crank angle Jor Ja,tropha biodiesel blends anddi(~selfuel at full load and rated speed. The simulation results 6f,blends like B20, B40, B70 andB 100 show lower work done than DIOO by about from 2% to' 11% respectively. The peakc: linder pressures are low with biodiesel blends in comparison to diesel and the heat release ofb)odiesel blends is lower than that of diesel fuel.

."" ...... ,-,...'".,,-"",, ..__.".""""._. __ .•.._".""""-"",,,,,,,,,,,,,-_--,_._._--

............300 J ...

i--DI00

, -"'" .. 820

- - 870 I-"'" • -.•8100 I

IFig.3 Comparison of cumulative work done for biodie,sel blends and diesel

fuels at full load and rated speed5 4 Effect Of Blend Ratio On Engine Thermal Efficien~y1 '1evariation of thermal efficiency with engine different loads is shown in Fig. 4. It was observedtl at with increasing the engine load, the thermal efficit:mcy illcr~a~e~, due .to the completec·1mbustj,on, lower viscosity and the presence of oxygen. Th.¢;tli~rir?:afieffideticy-,for biodie,sel-d esel blends (B20, B40, B70 and B 100) is lower than that of'<tliest;:!fu'eI by' aoourfrom 0.05% to022% respectively. The possible reasons for this reduction are lower'calofifi'c;value and increaseif fuel consumption ofbiodiesel- diesel blends than that of diesel fueL" '" ,... '.'-.i'·. i

119 JAVES, 9, 3D, 2014

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THEORETICAL INVESTIGA TIO!, OF THE PERFORMANCE OF DIESEL ENGINE FUELED BY BIODIESEL

.",j'

,I ' ~ '·,0:54,~. ~.

~~ 0 ..535

~ 0 ..5.3mE 0.525

~

0.55

0.5.'2

--DIOO

",.".-- 82.0

----B40

- - 8'70

0.515

1. 3 4 5 6

0.,;1 .................... { ....

Brake Power, kW

Fig.4 Comparison of thermal efficiency for biodiesel blends and diesel fuelsat different loads and rated speed

5 5 Effect Of Blend Ratio On Engine Specific Fuel ConsumptionF gure 5 shows the variation of specific fuel consumption with respect to engine loads. It issl own that specific fuel consumption decreases with increasing load. Specific fuel consumptionv:,lues for diesel-biodiesel blends (H20, B40, B70 and BIOO) were slightly higher than dieselfL el by about from 2.5% to 13% respectively. This is mainly due to the combined effects of therc !ative fuel density, viscosity and heating value of the blends. The higher density Of diesel-b odiesel blends has led to, more discharge of the fuel, thereby increasing the specific fuelc( 'nsymption,than diesel fuel.,~ . " I:'"':' r .--....~.l.;'-'..'-- ...-...._----_ ._.,::·~...,.-···---..-l·

'I I,,~. 0 S·.". .. :17

t ~.'if 0.1.7

-r:: 0,.1.65.2C.

I E 0.16::s'"I c: cussI 0u

! Qj 0.15! ::su..

I ~ 0.145, 'w

I C1!Q. 0.14'" 1.5

~•I

... ~... _ ................. ,

-0100

....... B20

----940

- - 870

- . -B100

~ 2.5 3.5 4 ..5 5.5

Brake Power, kW

Fig.S Comparison of specific fuel consumption for biodiesel blends anddiesel fuels at different loads and rated speed

6 Experimental analysisII four stroke, Kirloskar type, direct injection,'naturally aspirated,~ingle sylinder qi~s~l ~ngine, ithis 85 mm bore, 110 mm stroke, compression, ratio pf 17.5and a rated brake power; of 5.2 kW at1 ioa rpm,.is used fot the experimental anaIysis.Th{': e.ngine tests are carried out on qieselengineu ,jng diesel, H20 and B 100 as fuels. Jatropha biodh~sel was used 'a~,a fuel as it was anon ediblev ~getable Qil with 'properties close ,to diesel £\leI..The engine was. ,collpled.to .an, ed<i~ currentd mamometer and all experiments were carried out at constant speed of 1,500rPm., i , ' ., ./' piezoelectric pressure transducer Was instal1ed iri the .engine cylinder 'head.in order to,1.J1easure'tl e combustion pressure. The average pressure data from 200 consecutive cycles were used forc tlculating combustion parameters. Signal from the pressure transducer was fed to chargea nplifier. An encoder provides electrical signals in the form of pulse trains, which can betl qnslated into motion, direction, or position. Incremental encoder is installed to measure the

! ,UES, 9,.30, 2014 120

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THEORETICAL INVESTIGA nON OF THE PERFORMANCE OF DIESEL ENGINE FUELED BY BIODIESEL

eng ne crank angle and measures the rotational motion of a shaft. An Inductive proximity sensorsupl)lied a single pulse per revolution to mark TDC. Proximity Switch can be used to sense the"heal I of a:bolt attached to the shaft of the engine ..7. "alidation of the modelThl comparison between experimental and theoretical cylinder pressure at rated speed of 1500rpn and full load are shown in Fig.6. The experimental and theoretical cylinder pressures have

goo i agreer~~,! ..~\~!~~,,~.l2e~~_Qf_L?Q~~====:~,~~~l.!~~;~~~:' '_",, . A!,I!

<"--"'""~0100 (SirY1UI<1tion)

••••••• BlO (simLilation)

», ,~,~, ~ BI00 (simulation) ,

• ' 0100 {experhrH~ntal}

820 (experimental)

Bl00 (experinHmtal}

100 200 300 400

Crank Angle" Oegre,e

Fig.6 Comparison of calculat~d and experimental cylinder pressure for Diesel, B20and 8100 fuels at rated speed and full load

,

The trends of the cylinder pr~ssure curves for Jatropha biodiesel blends and diesel models andexp ~rimental are in the same 'trend as shown in Fig.6. Also the predictions of the model are veryclo~e to the experiwen.tal: Howev~~, the peak pressure values, respectively, for diesel, B20 andB ]('0 models are 6q:,4~ q~/'60-'b~r.and 58.21 bar, for diesel, B20 and BI00 experimental are58. '2 bar, 57.35 bar'<'ti'ld55.S'bar!Tlie relative error of cylinder pressure between theoretical and'exp ~rimental data for diesel fuel is less than 3%, the relative error of cylinder pressure betweenthel )retical and experimental 'data for B20 is less than 5 %, and the relative error of cylinderpre' sl1re between theoretical and experimental data for B 100 is less than 5 %. These resultsind cate that the assumpti6ns·ofthe model are reasonable.

8. (' 'ONCLUSIONPer 'armance cbaracteristics of diesel engine fueled by diesel- biodiesel blends are investigatedthe' ,retically and experimentally. The results indicated that: .

1- A quasi dimensional two ione combustion model has been carried out to predictthe engine performance in diesel engines. .

2- The model results show that the peak cylinder pressures, cylinder temperaturesand cumulafive work done are low with biodiesel blends by about from 1.5% to7% respectively for cylinder pressure from 1.5% to 7% respectively for cylindertemperature from 2% to 11% respectively for cumulative work done incomparison to diesel at full load and rated speed by about.

3- It is shown that specific fuel consumption values for diesel- biodiesel blends (820,B40, B70 and B 100) were slightly higher than diesel fuel by about from 2.5% to13% respectively, the thermal efficiency for biodiesel-diesel blends (B20, B40,B70 and BI00) were lower than that of diesel fuel by about from 0.05% to 0.22%respectively.

4- The results of the present model are well in agreement with experimental results.

121 JAUES, 9, 3D, 2014

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THEORETICAL INVESTIGA nON OF THE PERFORMANCE OF DIESEL ENGINE FUELED BY BIODIESEL

RF.'FERENCES ~ ; ..'.1- A.S.Ramadhas, SJayaraj, C.Muraaleedharan:;"Theortical modeling"arid ,experimental

studies on biodiesel-flleled engine", Renewable Energy, Vol.3·l, pp:181J~1826;'2006.2- G.H.Abd AHa, RA.Solimap, O.A.Badr et al,"Combustion quasi ..two;.zone predictive

model for dual fuel engines", 'Energy Conversion and ,Management, Vo1.42, pp)477-1498,2001. ... :. ".

3- M.P.Sudeshkumar , G.Devaradjane," Development of a simulation model. forcompression ignition engine running with ignition improved blend", Thermal Science,VoLlS, pp.1131-1144, 2011.

4- B.R.Prasath, P.Tamilporai, and M.F.Shabir " Theortical modeling and experimentalstudy of combustion and performance characteristics of biodiesel in turbocharged lowheat rejection D.I diesel engine", World Academy of Science, Engineering andTechnology, 2001. ~

5- B.R.Prasath, P.Tamilporai, and M.F.Shabir " Two- zone modeling of diesel/biodieselblended fuel operated ceramic coated direct injection diesel engine", InternationalIournal of Energy and Environment, YoU, pp.l039-1056, 2010.

6- S.S.Pandian, G.Devaradjane," Theortical and experimental investigation of theperformance of vegetable oil operated CI engine", Deapartment of AutombileEngineering, Madras, Institute of Technology, Anna University, 2009.

7- N.V.Deshpande, M.K.Madnani,A. Ioshi et ai," Simulation and analysis of combustionand heat transfer in low heat rejection diesel engine using two zone combustion modeland different heat transfer models", SAE 2003-01-1067,2003.

8- M.Y.Ali, S.N.Mehdi, P.R.Reddy," Modeling and simulation of compression ignitionengine processes with Biodiesel",Department of Mechanical Engineering, 2008.

9- T.K.Gogoi, D.C.Barua~"A cycle simulation m0del for predicting the performance of adiesel engine fuelled by diesel and biodiesel blends", Energy, Vo1.35, pp.1317-1323,2010. .

10- Ramos, I.I.,"Intemal combustion engine modeling", Hemisphere publishing Corporation,U.S.A., 1989. .

11- K.Qi, L.Feng, X.Leng, et al,"Simulation of quasi-dimensional combustion mod~1 for. predicting diesel engine performance ", Applied Matematical Modeling, VoL35, pp.930-940,2011. .

12- N.Wats6n, "Turbocharging the internal combustion engine", Mac-Millanpub, London,1989. ' . ..' ,. ;"

13- Y.Shen, I.Bedford, I.S.Wichman,"Thermodynamic moqeIing of ~ires( i-njectionmethanol fueled engine", Applied Thermal Engineering, Vo1.29, pp.2379':'2385, 2009.

14- A.R.Binesh, S.Hossainpour, "Three dimensional modeling oLrpj?\.ture formation andcombustion in a direct injection heavy -duty engin.~~'"International. Iournal ofMechanical Industrial and Aerospace Engineering, Vo1.2"pp.214-219, 2008. .

15- Semin, KAbu Bakar, A.R. Ismail,"In'vestigation of diesel engine performance based onsimulation", Applied Iournal of Applied Sciences, Vo1.6, pp.61 0-617, 2008 .

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