Hi, I have a technical problem with the boundary condition I have a problem in the channel that I have to change one of my boundary between two types (Dirichlet boundary condition and no flux) periodically and I don't know what should I do. should I use MatLab Livelink.for example after time=90s I should change my boundary type to no flux please help me Thanks.
Hello, Hossein Dayyani
I have no experience of both MatLab Livelink and cosmol. I suppose cosmol may be CFD(computational fluid dynamics) code. MatLab Livelink can be used to
set boundary condition by MatLab language. I think problems are following two. One is how to use MatLab Livelink. Other is cosmol.
Your solving flow problem is looked to me, channel flow is suddenly stopped at middle of the channel. Usually this flow induced water hammer phenomena. Sound wave propagation in the liquid has an important role. If cosmol is based on incompressible flow model, solving water hammer is impossible since sound velocity in fluid becomes infinity. Firstly, you should investigate the flow model of cosmol、I think.
Sincerely,
Fumio Takahashi.
Hi
You can read this article at URL:
https://www.comsol.com/blogs/specifying-boundary-conditions-and-constraints-in-variational-problems/
thanks Hassan Nasser, I studied this but I think my problem is easier .I thought that I just have to use matlab livelink but someone suggested to me that I can define two study and after that i can add the soulution of first study to the second study as the initial value and then change boundary condition and run the second study and reapet it again for the first study
Apply both boundary conditions at once, but with two parameters a and b multiplied to the condition. Then use if statement, if(time>0 & time
René Christensen
I'm trying to do this but I do not know how to do it where should I define if stament I apply both boundaries (see appendix).Thanks.
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