Solving 5 nonlinear equations with fsolve
3 vues (au cours des 30 derniers jours)
Afficher commentaires plus anciens
I'm a newbie in matlab. I'm trying to solve the following nonlinear equation system but I don't know how:
Qevap-((500+0.85*(((0.711+0.56*15/100+0.73*(15/100)^2)*5.67*10^(-8)*(25+273.15)^4*(1-cos(30*pi/180))/2)-5.67*10^(-8)*(25+273.15)^4))*1.6*0.8*(1-0*2)*1-1.6*((32+6.4*2)*(Te-25)))=0;
Qcond-(2068.5072425+(-20.1259571429)*Tc+0.0701428571*Tc^2+(56.5615102375+(-0.0892494524)*Tc+(-0.0013878571)*Tc^2)*Te+(0.669960831250007+(-0.001477845238096)*Tc+0.000000357142857*Tc^2)*Te^2)=0;
Wcomp-(373.160515+(-0.7728)*Tc+0.0378095238*Tc^2+((-4.03604873)+0.2014116*Tc+0.0005034286*Tc^2)*Te+((-0.22703617375)+0.003774373809524*Tc+(-0.000001214285714)*Tc^2)*Te^2)=0;
Qcond-(70*(Tc-40))=0;
Qcond-(Wcomp+Qevap-12*(Tc-20))=0;
I already saw the help documentation but I don't understando how to solve for 5 equations.
0 commentaires
Réponses (1)
John D'Errico
le 28 Déc 2015
Modifié(e) : John D'Errico
le 28 Déc 2015
I would just use the symbolic toolbox, finding 8 solutions.
syms Qevap Te Wcomp Qcond Tc
E1 = Qevap-((500+0.85*(((0.711+0.56*15/100+0.73*(15/100)^2)*5.67*10^(-8)*(25+273.15)^4*(1-cos(30*pi/180))/2)-5.67*10^(-8)*(25+273.15)^4))*1.6*0.8*(1-0*2)*1-1.6*((32+6.4*2)*(Te-25)))==0;
E2 = Qcond-(2068.5072425+(-20.1259571429)*Tc+0.0701428571*Tc^2+(56.5615102375+(-0.0892494524)*Tc+(-0.0013878571)*Tc^2)*Te+(0.669960831250007+(-0.001477845238096)*Tc+0.000000357142857*Tc^2)*Te^2)==0;
E3 = Wcomp-(373.160515+(-0.7728)*Tc+0.0378095238*Tc^2+((-4.03604873)+0.2014116*Tc+0.0005034286*Tc^2)*Te+((-0.22703617375)+0.003774373809524*Tc+(-0.000001214285714)*Tc^2)*Te^2)==0;
E4 = Qcond-(70*(Tc-40))==0;
E5 = Qcond-(Wcomp+Qevap-12*(Tc-20))==0;
result = solve(E1,E2,E3,E4,E5)
result =
Qcond: [8x1 sym]
Qevap: [8x1 sym]
Tc: [8x1 sym]
Te: [8x1 sym]
Wcomp: [8x1 sym]
vpa(result.Qcond)
ans =
206096.8437659089227610369512416
-79872.272069545160204450007603734
1480.0008801680255734628586801899
13408.004024141292656129583676207
10377.849121673682022577971691659
118026.5590524018573505429634831
1430.3277485980905870082908902277 - 10413.553488331644261070420163996i
1430.3277485980905870082908902277 + 10413.553488331644261070420163996i
Voir également
Catégories
En savoir plus sur Calculus dans Help Center et File Exchange
Produits
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!