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I would like to solve an equation with the PDE interface in Comsol5.4.I use coefficient form and wonder if the coefficients can be dependent on the same varaible the equation is solving for?

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Hello, I would like to solve an equation with the PDE interface in Comsol5.4.I use coefficient form and wonder if the coefficients can be dependent on the same varaible the equation is solving for?

So, if the equation is solving for T, can I put the coefficients of the equation to be a function of T?

Looking forward to your reply.

Jin


2 Replies Last Post 7 juin 2020, 19:52 UTC−4
Magnus Ringh COMSOL Employee

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Posted: 4 years ago 1 juin 2020, 04:16 UTC−4

Hi Jin,

Yes, the coefficients of the equation can be functions of the dependent variables (and their derivatives).

Best regards, Magnus Ringh, COMSOL

Hi Jin, Yes, the coefficients of the equation can be functions of the dependent variables (and their derivatives). Best regards, Magnus Ringh, COMSOL

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Posted: 4 years ago 7 juin 2020, 19:52 UTC−4

Hi Jin,

Yes, the coefficients of the equation can be functions of the dependent variables (and their derivatives).

Best regards, Magnus Ringh, COMSOL

Hello, when using the coefficient type partial differential equation interface, my coefficient is a piecework function to solve the dependent variable Te. I defined the function of this coefficient in the component. When I filled this function into the corresponding option of the coefficient type partial differential equation interface, the following error occurred in the calculation and the error was reported as: find the undefined value. There are 9,821 equations, and in the matrix rows of the variable comp1.te you get non-numbers/infinity. What could be the cause?

Looking forward to your reply.

Jin

>Hi Jin, > >Yes, the coefficients of the equation can be functions of the dependent variables (and their derivatives). > >Best regards, >Magnus Ringh, COMSOL Hello, when using the coefficient type partial differential equation interface, my coefficient is a piecework function to solve the dependent variable Te. I defined the function of this coefficient in the component. When I filled this function into the corresponding option of the coefficient type partial differential equation interface, the following error occurred in the calculation and the error was reported as: find the undefined value. There are 9,821 equations, and in the matrix rows of the variable comp1.te you get non-numbers/infinity. What could be the cause? Looking forward to your reply. Jin

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