Heat Transfer Interations with while loops

Question

Javen Harris 2020-5-4

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/523019-heat-transfer-interations-with-while-loops

I've been working on this code for the past couple days. I'm tyring to get the interations to run and get a time for how long it will take for T(1,p) to get to 200 degrees. Everytime I run the code to that, it runs for more than 10 minutes.

%%
%Steady Temperature at each node
clc
clear
L=.25; h=4000; Tinf=40; den=7850; 
Cp=650;k=27.3; dx=5E-3;
diff=k/(den*Cp); Bi=(h*dx)/k;
Fo=(1/2)/(1+Bi);
dt_i=(Fo*dx^2)/diff;dt=1.3;
Ti=1200; 
Ts=Tinf;
T_goal=200;
for i=1:51
    x=(i-1)*dx;
    T(i,1)=Ti;
end
nodes=1:51;
table=[nodes; T'];
fprintf('Node           Initial Temperature\n')
fprintf('  %i                 %5.3f\n',table);
%%
p=1;
while T_goal<T(1,p)
    p=p+1;   
    t=dt*(p-1);
    for i=1:51
    %for Cp
    if 900<=T(i,p-1)
        Cp=650;
        elseif 745<=T(i,p-1)
        Cp=545+(17820/(T(i,p-1)-731));
        elseif 600<=T(i,p-1)
        Cp=666+(13002/(738-T(i,p-1)));
        else 20<=T(i,p-1)
        Cp=(425+7.73*10^-1*T(i,p-1))-(1.69*(10^-3)*(T(i,p-1)^2))+(2.22*(10^-6)*(T(i,p-1)^3));
       end
    
    %For k
    
    if 800<=T(i,p-1)
        k=27.3;
    else T(i,p-1)
        k=54-3.33*(10^-2)*T(i,p-1);        
    end
diff=k/(den*Cp);
Bi=h*L/k;
Fo=(diff*dt)/L^2;
        if i==1 
            T(i,p)= Fo*(2*T(i+1,p-1))+(1-2*Fo)*T(i,p-1);
        elseif i==51
            T(i,p)=2*Fo*(T(i-1,p-1)+Bi*Tinf)+(1-2*Fo-2*Bi*Fo)*T(i,p-1);
        else
            T(i,p)=Fo*(T(i-1,p-1)+T(i+1,p-1))+(1-2*Fo)*T(i,p-1);
        end
    end
end
T_i=T';