fzchyi
2008-08-02, 15:41
eq1=sym('(Tg-302)/(1/23.26+0.01/1.1)+h*(Tg-Tf)+hwg*(Tg-Tw)=0.7*600');
eq2=sym('h*(Tg-Tf)+h*(Tw-Tf)=q');
eq3=sym('1.128*V*1005*(Tf-302)/0.75/4.6/2.2=q');
eq4=sym('Tf=0.75*To+0.25*302');
eq5=sym('h*(Tw-Tf)+1/(1/8.72+0.2/0.49)*(Tw-299)+hwg*(Tw-Tg)=0');
eq6=sym('0.6*4.6*0.3/sqrt(1+1)*sqrt(2*9.8*2.5*(Tf-302)/302)=V');
eq7=sym('5.67*10^8*(Tg^2+Tw^2)*(Tw+Tg)/(1/0.8+1/0.94-1)=hwg');
eq8=sym('0.0267*Nu/2.5=h');
eq9=sym('4.9+0.0606*(V/4.6/0.04*0.04/0.000016*0.701*2*0.04/2.5)^1.2/(1+0.0909*(V/4.6/0.04*0.04/0.000016*0.701*2*0.04/2.5)^0.7*0.701^0.17)=Nu');
[Tg,h,Tf,hwg,Tw,q,To,Nu,V]=solve(eq1,eq2,eq3,eq4,eq5,eq6,eq7,eq8,eq9);
运行后提示：Warning: Explicit solution could not be found.
> In solve at 140
In sym.solve at 49
方程组应该有大于0的解。
方程中有什么问题，导致不能求解？应该怎么解方程组？
eq2=sym('h*(Tg-Tf)+h*(Tw-Tf)=q');
eq3=sym('1.128*V*1005*(Tf-302)/0.75/4.6/2.2=q');
eq4=sym('Tf=0.75*To+0.25*302');
eq5=sym('h*(Tw-Tf)+1/(1/8.72+0.2/0.49)*(Tw-299)+hwg*(Tw-Tg)=0');
eq6=sym('0.6*4.6*0.3/sqrt(1+1)*sqrt(2*9.8*2.5*(Tf-302)/302)=V');
eq7=sym('5.67*10^8*(Tg^2+Tw^2)*(Tw+Tg)/(1/0.8+1/0.94-1)=hwg');
eq8=sym('0.0267*Nu/2.5=h');
eq9=sym('4.9+0.0606*(V/4.6/0.04*0.04/0.000016*0.701*2*0.04/2.5)^1.2/(1+0.0909*(V/4.6/0.04*0.04/0.000016*0.701*2*0.04/2.5)^0.7*0.701^0.17)=Nu');
[Tg,h,Tf,hwg,Tw,q,To,Nu,V]=solve(eq1,eq2,eq3,eq4,eq5,eq6,eq7,eq8,eq9);
运行后提示：Warning: Explicit solution could not be found.
> In solve at 140
In sym.solve at 49
方程组应该有大于0的解。
方程中有什么问题，导致不能求解？应该怎么解方程组？