Discussion Forum

Dear All,
I am simulating motion of the solid particle (a sphere in 2D simulation) in the flat fluid channel. ALE defomable mesh and weak constraints are used. Remeshing is also necessary.
The problem I am encountering is that, after each remeshing, the location of the solid cylinder (u,t) and the flow velocity (u2,v2) of the fluid is correctly mapped. However, the solid's velocity (ut,vt) is not. They were set to 0 at each execution of remeshing. So the solid experience an acceleration process after each remeshing, which is definitely wrong, because remeshing in this precess is very frequent. I tried to map all the values in the asseminit function, but it does not work.
THe key code is listed below. I hope the experts and friends here can help me to solve this problem.
PS. I am using version 3.5a.
Many Thanks.

while t_st<5.0
if t_st>0.0e0
% mapping current solution to extended mesh
init = asseminit(fem,'init',fem0.sol,'xmesh',fem0.xmesh,'framesrc','ale',...
'outcomp',{'lm4','lm3','u2','p2','v2','v','u','lm6','lm5','y','x','Y','X','ut','vt'});
end

if t_st==0.0e0
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:5.0], ...
'maxorder',2, ...
'tout','tlist', ...
'estrat',1, ...
'stopcond','minqual1_ale-0.1', ...
'uscale','none');
else
fem.sol=femtime(fem, ...
'init',init,...
'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',[t_st:deltat:5.0], ...
'maxorder',2, ...
'tout','tlist', ...
'estrat',1, ...
'stopcond','minqual1_ale-0.1', ...
'uscale','none');
end


% Save current fem structure for restart purposes
fem0=fem;

% Get final time from solution
% Use a point where the particle can be located at any time point
% Here a position at the centre of the cylinder [xc,yc]
t_st=postinterp(fem,'t',[xc;yc])
solution{j}=fem;

% update structure and generate new mesh

fem=mesh2geom(fem,'srcdata','deformed','frame','ale','destfield',{'geom','mesh'});
fem.mesh=meshinit(fem,'hgrad',1.15);

end
% End loop