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1、第一题题目：编写一个P－R方程已知p、T求比体积v的计算机程序。计算R134a的比体积，并将结果与文献值进行比较。将计算结果与文献值列表，并计算相对偏差；将计算值与文献值画在p–v图上。1、比较饱和线上的比体积；2、比较等温线t=90℃的比体积；R134a:Tc=374.18K，pc=4.056MPa，ω=0.326，M=102.03一、计算过程P-R方程为：将P-R方程整理，用牛顿迭代法求v值f=RgT(v2+2bv-b2)-a(v-b)-P(v-b)(v2+2bv-b2)f1=RgT(2v+2b)-a-
2、P(3v2-3b2+2bv)根据v(k+1)=v(k)-f/f1经过数次迭代后既可求得P、T所对应的v值二、源程序（1）计算并比较饱和线上的比体积PrivateSubCommand1_Click()Dimb,k,RgAsDouble,iAsIntegerDimp(10),t(10),f(10),f1(10),v(10),v1(10),v2(10),a(10),at(10),tr(10)Picture1.Cls:Picture2.ClsTc=374.18:Pc=4056000:w=0.326k=0.37464
3、+1.5422*w-0.26992*w^2t(1)=246.7:t(2)=262.96:t(3)=273.73:t(4)=282.08:t(5)=288.87t(6)=294.7:t(7)=299.87:t(8)=304.47:t(9)=308.65:t(10)=312.54Fori=1To10p(i)=i*10^5tr(i)=t(i)/Tca(i)=(1+k*(1-Sqr(tr(i))))^2Rg=8.3145/0.10203at(i)=(0.45724*Rg^2*Tc^2*a(i))/Pcb=(0.07
4、78*Rg*Tc)/Pcv(i)=1Forn=1To5000f(i)=Rg*t(i)*(v(i)^2+2*b*v(i)-b^2)-at(i)*(v(i)-b)-p(i)*(v(i)-b)*(v(i)^2+2*b*v(i)-b^2)f1(i)=Rg*t(i)*(2*v(i)+2*b)-at(i)-p(i)*(3*v(i)^2-3*b^2+2*b*v(i))v1(i)=v(i)-f(i)/f1(i)IfAbs(v1(i)-v(i))>0.00001Thenv(i)=v1(i)EndIfNextnPicture1
5、.PrintFormat(v1(i),"##0.000000")Picture1.PrintNextiv2(1)=0.189737:v2(2)=0.098326:v2(3)=0.066694:v2(4)=0.050444:v2(5)=0.040612v2(6)=0.03387:v2(7)=0.029081:v2(8)=0.025428:v2(9)=0.022569:v2(10)=0.020228Fori=1To10v2(i)=Abs((v1(i)-v2(i))/v2(i))*100Picture2.Prin
6、tFormat(v2(i),"##0.000")Picture2.PrintNextiEndSub（1）计算并比较等温线t=80℃的比体积PrivateSubCommand1_Click()Dimb,k,RgAsDouble,iAsIntegerDimp(10)AsDouble,t(10)AsDouble,f(10)AsDouble,f1(10)AsDouble,v(10)AsDouble,v1(10)AsDouble,v2(10)AsDouble,a(10)AsDouble,at(10)AsDouble,
7、tr(10)AsDoublePicture1.Cls:Picture2.ClsTc=374.18:Pc=4056000:w=0.326k=0.37464+1.5422*w-0.26992*w^2Fori=1To10t(i)=353.15:p(i)=i*10^5tr(i)=t(i)/Tca(i)=(1+k*(1-Sqr(tr(i))))^2Rg=8.3145/0.10203at(i)=(0.45724*Rg^2*Tc^2*a(i))/Pcb=(0.0778*Rg*Tc)/Pcv(i)=1Forn=1To500
8、0f(i)=Rg*t(i)*(v(i)^2+2*b*v(i)-b^2)-at(i)*(v(i)-b)-p(i)*(v(i)-b)*(v(i)^2+2*b*v(i)-b^2)f1(i)=Rg*t(i)*(2*v(i)+2*b)-at(i)-p(i)*(3*v(i)^2-3*b^2+2*b*v(i))v1(i)=v(i)-f(i)/f1(i)IfAbs(v1(i)-v(i))>0.00001Thenv(i)=v1(i
