Temperature-dependent boundary conditions

4 次查看（过去 30 天）
Shengyue Shan
Shengyue Shan 2019-9-13
评论： Shengyue Shan 2019-9-14
Hello,
I am having some difficulty developing my code for a heat transfer process using pde toolbox. I got errors as shown below,
Error using sym>tomupad (line 1240)
Unable to convert 'pde.PDEModel' to 'sym'.
Error in sym (line 214)
S.s = tomupad(x);
Error in solve>getEqns (line 402)
a = sym(a);
Error in solve (line 226)
[eqns,vars,options] = getEqns(varargin{:});
Error in heat_toy (line 56)
results = solve(model,tspan);
My boundary condition are tempeature-dependent. The coefficients 'g' and 'q' are defined by functions g1 and q1 respecitvely, and are as written as below,
function value = g1(location,state)
value = h*Ta./(S(state.u).*D(state.u));
end
function value = q1(location,state)
value = h.*S(SpecificHeat(state.u).*D(state.u));
end
S and D are functions of temperature, and are written as shown below,
function value = S(u)
cp = A3*u.^2 + B3*u + C3;
end
function value = D(u)
rho = A2*u.^2 + B2*u + C2;
end
Is it the boundary condititions that are causing me errors? Is there any way to solve it?
Thank you very much!
Best regards,
SS

请先登录，再回答此问题。

采纳的回答

Ravi Kumar
Ravi Kumar 2019-9-14
Do you have PDE Toolbox in your installed products list? You can check this by executing 'ver' at the command prompt. If so, did you create the 'model' variable using model=createpde(....)?
Regards,
Ravi
  7 个评论
显示 5更早的评论
Ravi Kumar
Ravi Kumar 2019-9-14
Can you post the complete code?
I am guessing you are overwriting the model, like:
model = generateMesh(model)
Regards,
Ravi
Shengyue Shan
Shengyue Shan 2019-9-14
Hi Ravi,
I guess I figured it out. The error was caused by using function solve instead of solvepde. Thanks for your help!
Best regards,
Shengyue Shan

请先登录，再进行评论。

更多回答（0 个）

类别

在 Help Center 和 File Exchange 中查找有关 Geometry and Mesh 的更多信息

标签

产品

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by