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35Temperature (K)25002300210019001700150010 CA20 CA30 CA25 30 35 40 45 50 55 60 65 70 75 80Crank Angle (CA)FIGURE 4-8 Temperature-Crank angle diagram of water injection duration angleWhen considering relative temperature as shown in Figure 4-7 and Figure 4-8,these can be seen that the temperature decrease for the molar water injection-fuelratio ( XW) and water injection duration angle ( θW) increases gradually. Thedecreasing was approximately maximum value of 10 K, which only fluctuate slightlyaround this value and curves are almost the same for all of cases. These can be shownin Figure 4-4. After that, temperature may be seen an increase in the slope of thetemperature–crank angle. But it is just lower than the normal case, it having thedifference of temperature decreasing was approximately value of 25 K.The effects of changing the pressure mixing and temperature mixing were dueto the mass of combustion products in cylinder actually is at constant in cylinder andhigh temperature. When having low temperature of water injected add withcombustion products, their must have the changing in the cylinder. As followingfrom equation of state [10], pressure directly change with mass (mole) andtemperature indirectly change with mass (mole). So that, if mass (mole) of the sparkignition engine with water injection system increases, the new pressure must beingvalue more than the old value and the new temperature must being less than the oldvalue. Old values were defined from normal case.4.3 Performances of Water injection model varied Molar water injection-fuel ratioIn this section, the schematic from Figure 4-3 were used to analytically discussresults of performance parameters such as indicated means effective pressure (IMEP)and indicated thermal efficiency ( η)under effects the different of molar waterinjection-fuel ratio ( XW) and are divided into 3 modes for simulation with variable ofcompression ratio range (8-12), equivalence ratio range (0.8-1.2) and engine speedrange (1000-2500 RPM), respectively. These will be described as following.4.3.1 Performance of the water injection model at different compression ratio ( r)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 compression ratio ( r), varied from 8, 9, 10, 11 and 12,respectively.
36IMEP (MPa)1.0501.0251.0000.9750.9500.925Normal0.5Nw/Nf1.0Nw/Nf1.5Nw/Nf2Nw/Nf8 9 10 11 12Compression ratioFIGURE 4-9 IMEP-Compression ratio with molar water injection-fuel ratioThermal efficiency (%)4342414039383736Normal0.5Nw/Nf1.0Nw/Nf1.5Nw/Nf2Nw/Nf8 9 10 11 12Compression ratioFIGURE 4-10 Thermal efficiency-Compression ratio withmolar water injection-fuel ratiosAccording to Figure 4-9 and Figure 4-10, these results help to predict the bestthe molar 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 differencein both from the normal case. The both cases increasing were approximately value of25,000 Pa and 1% of IMEP and thermal efficiency respectively which only fluctuatesslightly around this value for all of compression ratio increases and curves almost thesame for each the molar water injection-fuel ratio increases.Theoretically, Indicated efficiency increase with increasing compression due tocompression ratio has a great effect on the terminal combustion pressure [6]. Theincrease of compression ratio results in increase of cylinder top pressure as well as
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 50 and 51: 37cylinder temperature. So, a more
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 64 and 65: 51Temperature (K)240021001800150012
Page 66 and 67: 53When considering relative tempera
Page 68 and 69: 55Temperature (K)220019001600130010
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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