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help with asseminit for remeshing
Posted Feb 19, 2011, 12:57 p.m. EST Microfluidics, Structural Mechanics Version 3.5a 3 Replies
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I 've posted two messages on this problem, but no one reply, perhaps because I did not make my questions clear.
Now I have pin pointed the segment where the problem arises.
I am simulating a fluid-structure interaction problem which requires remeshing. However, after solution of the problem and remesh the deformed structure, I found the displacement (u,v) of the solid structure was successfully mapped, while the veolity (ut,vt) is not.
After execution of the following code segments, I found init.ut contains only 0 values, although the values of fem0.sol.ut are all non-zero. Anyone knows where I am wrong?
For your kind help please.
Thanks
ZR
........................
fem.sol=femtime(fem, ...
'blocksize',1000, ...
'atol',{'0.02'}, ...
'solcomp',{'lm4','lm3','u2','p2','v2','v','u','lm6','lm5','y','x'}, ...
'outcomp',{'lm4','lm3','u2','p2','v2','v','u','lm6','lm5','y','x','Y','X','ut','vt'}, ...
'tlist',[0:deltat:endt], ...
'maxorder',2, ...
'tout','tlist', ...
'estrat',1, ...
'stopcond','minqual1_ale-0.1', ...
'uscale','none');
fem0=fem;
% update structure and generate new mesh
fem=mesh2geom(fem,'srcdata','deformed','frame','ale','destfield',{'geom','mesh'});
fem.mesh=meshinit(fem,'hgrad',1.15);
fem.xmesh=meshextend(fem);
% mapping current solution to extended mesh
init = asseminit(fem,'init',fem0.sol,'xmesh',fem0.xmesh,'framesrc','ale','T',endt);
-------------------------------------
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I do not know if it's related but in 3.5s in the solver section (if I remeber right) there is somewhhere a check box to add the time derivatives (perhaps it was only for the postprocessing). Normally, COMSOL control it if required, perhaps it should be on. There are a few older threads about it's effect, try a search
--
Good luck
Ivar
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The option for derivative is only for the output in the solver, and for processing.
The problem might be with my call to asseminit, because the derivatives (ut,vt) is obtained and stored in fem0.sol.
The asseminit call did not map the derivative ut and vt, while the deformation terms u and v were correctly mapped.
For your kind guidance please.
Regards.
ZR
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Anyone has an idea about this problem? I run the simulation save current data to fem0, remesh the deformed structure and map the velocity (ut) and deformation (u) to the new one , I found u is OK, while ut is all zero.
The code is as follows: (I am using Comsol 3.4)
------------------------------------------------
fem0=fem;
% update structure and generate new mesh
fem=mesh2geom(fem,'srcdata','deformed','frame','ale','destfield',{'geom','mesh'});
fem.mesh=meshinit(fem,'hgrad',1.15);
fem.xmesh=meshextend(fem);
% mapping current solution to extended mesh
init = asseminit(fem,'init',fem0.sol,'xmesh',fem0.xmesh,'framesrc','ale','T',endt);
--------------------------------------------------------------------------------------
THe results:
fem0.sol.u ={correct nontrivial array of data};
fem0.sol.ut ={correct nontrivial array of data};
init.u={correct nontrivial array of data};
init.ut={wrong array of 0}
I do hope someone can help me.
I have a misterious gift for you.
Thanks and regards.
ZR