fortran运行结果不合理，求大佬们的帮忙
program enthalpyimplicit none
!This program aim to calculate the enthalpy of h2s hydrate dissociation in the presence of water
double precision P,T,xh2s,n
double precision dPdT,H1,V,Hdiss,Hsolve
print*,"please imput temperature (K)"
read*,T
print*,"please imput pressure (MPa)"
read*,P
print*,"please imput hydation number"
read*,n
print*,"please imput mole fraction of h2s in liquid"
read*,xh2s
call dissenthalpy(Hdiss,T,dPdT,V)
call solveenthalpy(Hsolve,xh2s,n)
H1=Hdiss+Hsolve
print*,"H1=",H1
pause
! return
end
subroutine Derivative(dPDT,T)
double precision dPdT,T,e(4)
data e/-436.1,4.6,-0.018,0.0000196/
dPdT=e(1)+e(2)*T+e(3)*T**2+e(4)*T**3 !MPa/K
print*,"dPdT=",dPdT
return
end
subroutine Totalmolarvolume(V,Vliquid,Vgas,Vhydrate)
double precision V,Vliquid,Vgas,Vhydrate,xh2s,n,parameter1,parameter2,density2,l(4) !density1,molecularweight2,V4,molecularweight,h(6)
!data h/44.202,2544.564,-35.957,0.191,-4.488E-4,3.965E-7/
data l/21.90583,-0.21947,7.33695E-4,-8.18347E-7/
!calculating the molar volume change of solution
parameter1=0.0000045
parameter2=0.000018
Vliquid=xh2s*parameter1+parameter2 !m3/mol
!calculating the molar volume change of hydrate
! density1=1050!kg/m3 !this value is guess
! molecularweight2=0.1461 !kg/mol
Vhydrate=1.391E-4 !m3/mol, Vhydrate=molecularweight/density1
!calculating the molar volume change of vapor
!density2=h(1)+h(2)*T+h(3)*T**2+h(4)*T**3+h(5)*T**4+h(6)*T**5 !kg/m3
!molecularweight=0.034 !kg/mol
! Vgas=molecularweight/density2 !m3/mol
Vgas=l(1)+l(2)*T+l(3)*T**2+l(4)*T**3
!calculating the total molar volume
V=(1-(n*xh2s)/(1-xh2s))*Vgas+n*Vliquid-Vhydrate !m3/mol
print*,"Vliquid=",Vliquid
print*,"Vhydrate=",Vhydrate
print*,"Vgas=",Vgas
print*,"V=",V
return
end
subroutine dissenthalpy(Hdiss,T,dPdT,V)
double precision Hdiss,T,dPdT,V,Vliquid,Vgas,Vhydrate
call Derivative(dPDT,T)
call Totalmolarvolume(V,Vliquid,Vgas,Vhydrate)
Hdiss=1000000.0*dPdT*T*V
print*,"Hdiss=",Hdiss
return
end
subroutine solveenthalpy(Hsolve,xh2s,n)
double precision Hsolve,xh2s,n
Hsolve=17960.0*n*xh2s/(1-xh2s) !J/mol
print*,"Hsolve=",Hsolve
return
end
按照上面的运行结果，我输入T=274.15 K, P=0.118 MPa，n=6.2, xh2s=0.004的情况下，输出结果为：
dPdT=-124.007293931873
Vliquid= -4.165183558045402E+056
Vhydrate=1.390999968862161E-004
Vgas=1.013072811542869E+018
V=3.855278546349224E+118
Hdiss= -1.310663612078491E+129
Hsolve= 447.196787148594
H1= -1.310663612078491E+129
上述高亮部分结果不对，为什么会出现10的129次方呢，可我又不知道为什么，本人小白一枚，求各位大佬支招
Totalmolarvolume 函数里 xh2s，T，n 这三个变量，没有定义，也没有赋值。就直接使用，当然会出错。
建议：
1. 要写 implicit none，每个程序单元都要写。
2. 学习 debug 单步调试。 fcode 发表于 2020-1-22 21:16
Totalmolarvolume 函数里 xh2s，T，n 这三个变量，没有定义，也没有赋值。就直接使用，当然会出错。
建议 ...
实际上，只要主程序和每个module里的开头写上就可以了吧
我实际测试的结果是，只要这样写了，之后的所有子程序和函数里都不能有未声明的变量了 liudy02 发表于 2020-1-24 01:56
实际上，只要主程序和每个module里的开头写上就可以了吧
我实际测试的结果是，只要这样写了，之后的所有 ...
Implicit None 如果写在module里，那么module里contains的过程都有效。
但是楼主玩的都是外部子程序，需要每个程序单元都写 fcode 发表于 2020-1-24 09:04
Implicit None 如果写在module里，那么module里contains的过程都有效。
但是楼主玩的都是外部子程序，需 ...
原来如此，谢谢~
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