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Boundary Intergration Coupling Variables
Posted Nov 5, 2009, 8:54 a.m. EST 1 Reply
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Hello,
For my problem, i need to define two boundary integration coupling variables. 1 calculating the force(integration of pressure), outside of a surface and the other calculating this force on the inside. Later i can use a global expression to calculate the difference between the two.
However i am having difficulties trying to scirpt this in Matlab. I've tried doing it in Comsol but to no affect. Problem is both coupling variables so up at each group of boundaries while only one of them should. I hope i can make this more clear by showing my Matlab code:
% Integration coupling variables
clear elem
elem.elem='elcplscalar';
elem.g={'1'};
elem.var={'FaIn','FaOut'};
elem.global={'1'};
elem.maxvars={'2'};
clear src;
src.ind={{'4','5','9'},{'17','18','22'}};
src.expr={{'p*nz'},{'p*nz'}};
src.ipoints={{'4'},{'4'}};
elem.src{1}={{},{},src};
fem.elemcpl=elem;
Thanks in advance,
AM
For my problem, i need to define two boundary integration coupling variables. 1 calculating the force(integration of pressure), outside of a surface and the other calculating this force on the inside. Later i can use a global expression to calculate the difference between the two.
However i am having difficulties trying to scirpt this in Matlab. I've tried doing it in Comsol but to no affect. Problem is both coupling variables so up at each group of boundaries while only one of them should. I hope i can make this more clear by showing my Matlab code:
% Integration coupling variables
clear elem
elem.elem='elcplscalar';
elem.g={'1'};
elem.var={'FaIn','FaOut'};
elem.global={'1'};
elem.maxvars={'2'};
clear src;
src.ind={{'4','5','9'},{'17','18','22'}};
src.expr={{'p*nz'},{'p*nz'}};
src.ipoints={{'4'},{'4'}};
elem.src{1}={{},{},src};
fem.elemcpl=elem;
Thanks in advance,
AM
1 Reply Last Post Nov 5, 2009, 9:47 a.m. EST
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Posted:
1 decade ago
Ok, i have managed to get the boundary conditions the way i want them. However everytime i do a simulation the solver keeps on iterating and never seems to go pas 4e-3 convergence, after 4 iterations the stepsize doesnt decrease any further. Why does this happen?
My code:
% Coupling variable elements
clear elemcpl
% Integration coupling variables
clear elem
elem.elem = 'elcplscalar';
elem.g = {'1'};
src = cell(1,1);
clear bnd
bnd.expr = {{{},'p*nz',{}},{{},{},'p*nz'}};
bnd.ipoints = {{{},'4',{}},{{},{},'4'}};
bnd.frame = {{{},'ref',{}},{{},{},'ref'}};
bnd.ind = {{'1','2','3','6','7','8','10','11','12','13','14','15','16', ...
'19','20','21','23'},{'4','5','9'},{'17','18','22'}};
src{1} = {{},{},bnd,{}};
elem.src = src;
geomdim = cell(1,1);
geomdim{1} = {};
elem.geomdim = geomdim;
elem.var = {'FaIn','FaOut'};
elem.global = {'1','2'};
elem.maxvars = {};
elemcpl{1} = elem;
fem.elemcpl = elemcpl;
Thanks
My code:
% Coupling variable elements
clear elemcpl
% Integration coupling variables
clear elem
elem.elem = 'elcplscalar';
elem.g = {'1'};
src = cell(1,1);
clear bnd
bnd.expr = {{{},'p*nz',{}},{{},{},'p*nz'}};
bnd.ipoints = {{{},'4',{}},{{},{},'4'}};
bnd.frame = {{{},'ref',{}},{{},{},'ref'}};
bnd.ind = {{'1','2','3','6','7','8','10','11','12','13','14','15','16', ...
'19','20','21','23'},{'4','5','9'},{'17','18','22'}};
src{1} = {{},{},bnd,{}};
elem.src = src;
geomdim = cell(1,1);
geomdim{1} = {};
elem.geomdim = geomdim;
elem.var = {'FaIn','FaOut'};
elem.global = {'1','2'};
elem.maxvars = {};
elemcpl{1} = elem;
fem.elemcpl = elemcpl;
Thanks