How do I solve a single for temperature with one PDE containing dT/dx and dT/dt?
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I have a single differential equation. I am trying to solve a heat transfer problem. The equation relates the temperature of the near surroundings of a panel (T), and the front and backside temperature of a panel (Tf and Tr). This leaves me with 3 variables and 3 unknowns. I can somewhat relate the two together, like Tfront will be facing a heat source and so will definitely be higher than T rear at any point in time. But thats about it. Any help is appreciated.
EDIT
After going through the equations again, i've noticed that the two temperature terms can be combined with a dx to make a dT/dx. So now I have a single differential equation with one dT/dt term and a dT/dx term. How do I solve this now? I don't know what syntax I should use for the ode45 script, since I have a parameter with respect to another variable.
9730*dT/dt=(.1*(1-(((-2.26376*(10^-4))*T^2)+((6.9035*(10^-2))*T)+26.1855203))... cosd(24.5)(1006.5)+(5.672*10^(-8))*.9*T^4)+dT/dx
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Answers (2)
Star Strider
on 30 Jan 2018
If you need to estimate the other parameter, see Optimizing a Simulation or Ordinary Differential Equation (link).
Torsten
on 2 Feb 2018
Edited: Torsten
on 2 Feb 2018
This is a partial differential equation for T.
If [a;b] is the x-interval on which you want to solve the equation and a=x1<x2<...<xn=b is a spatial grid, you can discretize dT/dx in x=xi as (T(i+1))-T(i))/(x(i+1)-x(i)) for 1<=i<n.
The resulting system of ordinary differential equations for the temperatures in the grid points then reads
9730*dT(i)/dt=(.1*(1-(((-2.26376*(10^-4))*T(i)^2)+((6.9035*(10^-2))*T(i))+26.1855203))...
* cosd(24.5)*(1006.5)+(5.672*10^(-8))*.9*T(i)^4)+(T(i+1))-T(i))/(x(i+1)-x(i))
for 1<=i<n.
and a specified temperature T(n) at x=xn.
You can use ODE15S to solve.
Look up "method of lines" for more details.
Best wishes
Torsten.
3 Comments
Torsten
on 6 Feb 2018
https://de.mathworks.com/matlabcentral/answers/371313-error-in-solving-system-of-two-reaction-diffusion-equations
Best wishes
Torsten.
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