I try to simulate laser manufacturing process. IT involves a lot of layer-by-layer build up. So I use comsol and make loop simulation by using matlab. I can do loop simulation of layer-by-layer but I cannot use the previous loop result as an initial condition of the next loop. Can anyone give me an idea how to handle this problem?
Hi,
In the Solver, normally under the "defined variables" node, you can choose the way the software "guess" the initial values. You have two kind of initial values, one for "variables solved for" and another for "variables not solved for". For each kind you can choose the type of initial values : "initial value" or "Solution" type. Select Solution type then you will have to choose which solution you would like to use as an initial value. Generally, you will choose "Last" if your performing a transient simulation.
Regards,
Mohamed
Hi,
In the Solver, normally under the "defined variables" node, you can choose the way the software "guess" the initial values. You have two kind of initial values, one for "variables solved for" and another for "variables not solved for". For each kind you can choose the type of initial values : "initial value" or "Solution" type. Select Solution type then you will have to choose which solution you would like to use as an initial value. Generally, you will choose "Last" if your performing a transient simulation.
Regards,
Mohamed
Thank you very much Mohamed for your invalueable suggestion
I will try it and let you know how it work out.
Joe
@ Nadeem - What is your version 4.3a or 4.3b ? I have attached the screen shot of 4.3a for your case.
@ Hakeem Niyas- I really appreciate your kind and prompt response. This is screen shot for settings. However, it has only :Values of variables not solved for".
Hello Nadeem,
Can you give us more informations about your model ? What type of simulation are you performing ? what is the solver type used, static, transient ? Is there multiphysics ? Parametric sweep, controled loop under matlab ?
All these information can be useful. If you can attach a simplified version of your model it would be great also.
Regards,
Mohamed Amine Khalf
Dear Nadeem, here is my email : [email protected]. You can send me your model but i can't work on it until monday. As far as I understand your problem, I think that you should try to ramp your load progressively using a comsol bult-in function with a smoothing parameter that has to be adjusted ( the default one is ok).. Another thing, fully coupled solver is much more stronger then iterative solver in case of high non-linear problems even if it's much more memory consumming. Of course you can also work on your mesh density.
@ Nadeem - I guess you are using 4.3b !!! The screenshot which I have shared is from my 4.3a version - Please try if you have 4.3a. Backward compatibility is not available for comsol - once a file is just opened in 4.3b - it cant be opened in 4.3a
@ Nadeem - I guess 4.3 is not having the feature - 4.3a is having that
@Nadeem - You have two functions : ramp (rm1) and step (step1). I suggest to use ramp function in your case. You will find these functions under the project tree in Definition - Functions
It is a very interesting discussion. I am having a similar kind of problem in RF module 4.4a,. I am solving a optics problem. I have a solution set for a parametric sweep from 900nm to 1500nm with a step of 5[nm]. This solution is obtained at " epsilon= eps0" for a material in my model. Now i want to define "epsilon= eps0+normE" and run the parametric sweep for the same range at same interval.
While running for the wavelength of 900nm, normE should be from the earlier simulation value at 900nm.
similarly for 905 nm, normE should be from the earlier simulation value at 905nm..and so on till 1500nm. So how do i call this in my study node.
Thanks in advance for support.
Hello , I am learning how to use comsol. So let;s supose a 1D heat transfer problem (transient , without heat source and convection) How can I set a parabolic distribution a initial condition, for example T(x,0) = x^2. how can i do that in comsol? thanks
Under heat transfer module, you should see 'Initial Values' submodule. That's where you specify you initial temperature, and you can directly specify x^2 in it, just make sure you tell COMSOL what unit you are using. Say if you want K and x is in meter, you can put x^2 [K/m^2] in the initial temperature.
Thank you so much dear Colleague, one last question, If I want to set thermal conductivity as a function of temperature ( i mean k=f(Temp) with a table of values for a given temperature, an especificif conductivity) How can i do that??
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