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37cylinder temperature. So, a more value of compression may be chosen for thissimulation, it follows a similar trend to the spark ignition engine and 0.5 value of themolar water injection-fuel ratio was chosen for this simulation. It gives the thermalefficiency that is not much different value with other cases, however, a hightemperature and pressure environment may cause knock to happen inside thecombustion chamber and auto ignition may occur as the compression ratio increase.4.3.2 Performance of the water injection model at different equivalence ratio ( φ )This simulation test was run at 2,000 rpm, equivalence ratio of 0.8 and waterinjection duration angle ( θW) of 10 CA with the different molar water injection-fuelratio ( XW) while using different equivalence ratios ( φ ), varied from 0.8, 0.9, 1.0, 1.1and 1.2, respectively.1.301.20IMEP (MPa)1.101.00Normal1.0Nw/Nf2Nw/Nf0.5Nw/Nf1.5Nw/Nf0.900.8 0.9 1 1.1 1.2Equivalence ratioFIGURE 4-11 IMEP-Equivalence ratio with the molar water injection-fuel ratio43Thermal efficiency (%)4038353330Normal0.5Nw/Nf1.0Nw/Nf1.5Nw/Nf2Nw/Nf0.8 0.9 1 1.1 1.2Equivalence ratioFIGURE 4-12 Thermal Efficiency-Equivalence ratio withmolar water injection -fuel ratio
38According to Figure 4-11 and Figure 4-12, this results help to predict the bestmolar water injection -fuel ratio to simulate a spark ignition engine with waterinjection. The indicated mean effective pressure (IMEP) and thermal efficiency risesas the molar water injection-fuel ratio increases. However it is not much difference inthe both from the normal case. The both cases increasing was approximately value25,000 Pa and 1% of IMEP and thermal efficiency respectively which only fluctuateslightly around this value for all of equivalence ratio case. And these curves arealmost the same for each the molar water injection-fuel ratio case which werecompared with normal case. Indicated efficiency increase with increasingcompression ratio, is maximized by lean combustion, and is practically independentof the initial temperature and initial pressure.Theoretically, in actual engines or simulation, maximum efficiency occurs atstoichiometric or slightly lean, excessive dilution of the change with air degrades thecombustion [6]. However, it depends on application any types of fuels provided [6].In this case, a 0.8 value of equivalence ratio was chosen for gasoline that may beoptimized value for this simulation which gives IMEP and the thermal efficiency thatdoes not look different much for all of equivalence ratio case.4.3.3 Performance of the water injection model at different engine speeds (RPM)This simulation test was run at 2,000 rpm, equivalence ratio of 0.8 and waterinjection duration angle ( θW) of 10 CA with the different molar water injection-fuelratio ( XW) while using different engine speed, varied from 1000, 1500, 2000, 2500and 3000, respectively.IMEP (MPa)1.0501.0251.0000.9750.9500.9250.9000.8750.850Normal1.0Nw/Nf2Nw/Nf0.5Nw/Nf1.5Nw/Nf1000 1500 2000 2500 3000RPMFIGURE 4-13 IMEP-RPM with the molar water injection-fuel ratio
Page 1 and 2: ANALYSIS OF WATER INJECTION INTO HI
Page 3 and 4: Thesis CertificateThe Graduate Coll
Page 5 and 6: ชื่อ : นายปรม
Page 7 and 8: TABLE OF CONTENTSPageAbstract (in E
Page 9 and 10: LIST OF TABLESTablePage3-1 Solution
Page 11 and 12: LIST OF FIGURES (CONTINUED)FigurePa
Page 13 and 14: LIST OF ABBREVIATIONS, SYMBOLS AND
Page 15 and 16: CHAPTER 1INTRODUCTION1.1 Background
Page 17 and 18: 31.6.6 Water injected is assumed to
Page 19 and 20: 6for these working fluid models can
Page 22 and 23: CHAPTER 3METHODOLOGY FOR ANALYSIS O
Page 24 and 25: 11perform the necessary calculation
Page 26 and 27: 13h b P T w−0.2 0.8 −0.55 0.8=
Page 28 and 29: 15the procedure required Nitrogen(
Page 30 and 31: 171N22 NEq.3-461 1O+2N2 NOEq.3-472
Page 32 and 33: 19∂y1 cy ∂y1 cy ∂y 1 c ∂y 1
Page 34 and 35: 211/2( cy )∂y ∂∂c ∂y∂T
Page 36 and 37: 23[ A][ ∂y/ ∂ P] + [ ∂f / ∂
Page 38 and 39: 25⎛ • • •ln ln ⎞⎛⎞( )
Page 40 and 41: 27( θ= −π)θ>θ bθ>θ W( θ=π
Page 42 and 43: CHAPTER 4RESULTS AND DISCUSSIONThis
Page 44 and 45: 31FIGURE 4-1 Comparison of an actua
Page 46 and 47: 33FIGURE 4-4 Schematic of the port
Page 48 and 49: 35Temperature (K)250023002100190017
Page 52 and 53: 39Thermal efficiency (%)43424140393
Page 54 and 55: 41Theoretically, the high useful co
Page 58 and 59: 45injection-fuel ratio increases gr
Page 62 and 63: 49When considering relative tempera
Page 66 and 67: 53When considering relative tempera
Page 70 and 71: CHAPTER 5CONCLUSIONS AND SUGGESTION
Page 72 and 73: REFERENCES1. Ricardo, H.R. The High
Page 74: APPENDIX ADerivative equations of i
Page 78 and 79: 64TABLE A-3 Curve fit coefficients
Page 80 and 81: 66TABLE A-5 Curve fit coefficients
Page 82 and 83: 68The following is the derivative v
Page 84 and 85: 70From the definition of entropyh =
Page 86 and 87: 72• ⎛ ⎞ • ⎛Tb∂u •b∂
Page 88 and 89: 74• ⎛1 ⎞ •∂u ⎛∂ ∂
Page 90 and 91: 76⎛ • • •ln ln ⎞⎛⎞( )
Page 92 and 93: 78The following is the derivative v
Page 94 and 95: 80From the definition of entropy h
Page 96 and 97: 82• ⎛ Tb u ⎞ • • ⎛bmTb
Page 98 and 99: 84• ⎛1 ⎞ • •∂u ⎛ ⎞
Page 100 and 101:
86• • • ⎛ u ⎞bmb( hW ub)
Page 102 and 103:
88Appendix D MATLAB program scripts
Page 104 and 105:
90[thetawater,pTbWQlHl2]=ode45('Rat
Page 106 and 107:
92-0.69353550E-14 -0.14245228E+05 0
Page 108 and 109:
940.21*(1-phi) 0 0]';dcdT=0;else %
Page 110 and 111:
96dfdp=zeros(4,1);dYdT=zeros(11,1);
Page 112 and 113:
98dcdT(1)=-dKdT(1)*sqrt(patm)/K(1)^
Page 114 and 115:
100Iter=Iter+1;[hb,u,v,s,Y,cp,dlvlT
Page 116 and 117:
102yprime(2)=-Const1/cpb/x*Qconvb+v
Page 118 and 119:
104masswaterin=massfuel*mwpmf;% Tot
Page 120 and 121:
106savefile = 'Volume.mat';RTWV=RTW
Page 122 and 123:
108p=pTarray(:,1);T=pTarray(:,2);hc
Page 124 and 125:
110gamma_der_tautau = 0;for i = 1 :
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