FEATool Multiphysics  v1.17.0
Finite Element Analysis Toolbox
ex_heattransfer10.m File Reference

Description

EX_HEATTRANSFER10 Conjugate heat transfer test example with multiple domains.

[ FEA, OUT ] = EX_HEATTRANSFER10( VARARGIN ) Sets up and solves a multiple domain conjugate heat transfer example.

Accepts the following property/value pairs.

Input       Value/{Default}        Description
-----------------------------------------------------------------------------------
hmax        scalar {0.0005}        Max grid cell size
sf_u        string {sflag2}        Shape function for velocity
sf_p        string {sflag1}        Shape function for pressure
sf_T        string {sflag1}        Shape function for temperature
solver      string openfoam/fenics/{} Use OpenFOAM, FEniCS, or default solver
iplot       scalar 0/{1}           Plot solution and error (=1)
                                                                                  .
Output      Value/(Size)           Description
-----------------------------------------------------------------------------------
fea         struct                 Problem definition struct
out         struct                 Output struct

Code listing

 cOptDef = { 'hmax',     1/10;
             'sf_u',     'sflag1';
             'sf_p',     'sflag1';
             'sf_T',     'sflag1';
             'turb',     [];
             'solver',   '';
             'iplot',    1;
             'tol',      0.1;
             'fid',      1 };
 [got,opt] = parseopt( cOptDef, varargin{:} );
 fid       = opt.fid;


% Geometry definition.
 fea.sdim         = { 'x' 'y' };
 fea.geom.objects = { gobj_rectangle(0, 1, 0, 0.5), ...
                      gobj_rectangle(0, 1, 0.5, 1, 'R2') };


% Grid generation.
 n = round(1/opt.hmax);
 fea.grid = gridmerge( rectgrid(2*n, n, [0, 1; 0, 0.5]), 3, rectgrid(2*n, n, [0, 1; 0.5, 1]), 1);
 fea.grid.s( selcells(fea,'y >= 0.5') ) = 2;
 fea.grid = gridbdrx(fea.grid);


% Problem definition.
 fea = addphys(fea,@navierstokes);     % Add Navier-Stokes equations physics mode.
 fea.phys.ns.eqn.coef{1,end} = {1, 1000};
 fea.phys.ns.eqn.coef{2,end} = {1, 959e-6};
 fea.phys.ns.prop.active(:,1) = 0;
 fea.phys.ns.bdr.sel(6) = 2;
 fea.phys.ns.bdr.coef{2,end}{1,6} = 0.00001;
 fea.phys.ns.bdr.sel(4) = 4;

 fea = addphys(fea,@heattransfer);     % Add heat transfer physics mode.
 fea.phys.ht.eqn.coef{1,end} = {8000, 1000};
 fea.phys.ht.eqn.coef{2,end} = {450, 4181};
 fea.phys.ht.eqn.coef{3,end} = {80, 4181*959e-6/6.62};
 fea.phys.ht.eqn.coef{4,end} = {0, 'u'};
 fea.phys.ht.eqn.coef{5,end} = {0, 'v'};
 fea.phys.ht.bdr.sel([1,6]) = 1;
 fea.phys.ht.bdr.coef{1,end}{1} = 400;
 fea.phys.ht.bdr.coef{1,end}{6} = 300;
 fea.phys.ht.bdr.sel([2,3,5]) = 3;
 fea.phys.ht.eqn.coef{end}{1} = 300;
 fea.phys.ht.eqn.coef{end}{2} = 300;


% Parse and solve problem.
 fea = parsephys(fea);
 fea = parseprob(fea);

 if( strcmp(opt.solver,'fenics') )
   fea = fenics( fea, 'fid', fid );
 elseif( strcmp(opt.solver,'openfoam') )
   fea.sol.u = openfoam( fea, 'fid', fid, 'ddtScheme', 'CrankNicolson', 'endTime', 1e5, 'maxDeltaT', 1e5/100, 'nproc', 1, 'turb', opt.turb );
 else
   fea.sol.u = solvestat( fea, 'fid', fid, 'maxnit', 50 );
 end


% Postprocessing.
 if( opt.iplot>0 )
   figure
   subplot(1,2,1)
   postplot( fea, 'surfexpr', 'sqrt(u^2+v^2)', 'arrowexpr', {'u' 'v'} )
   title('Velocity field')

   subplot(1,2,2)
   postplot( fea, 'surfexpr', 'T' )
   title('Temperature')
 end

% Average temperature at outlet.
 out.ref = [1.4111e-5, 309.7998, 394.3849];
 out.val = [evalexpr('u',[1;0.75],fea), ...
            evalexpr('T',[1;0.75],fea), ...
            evalexpr('T',[1;0.5],fea)];
 out.err = abs(out.val - out.ref)./out.ref;
 out.pass = all(out.err < opt.tol);

 if( nargout==0 )
   clear fea out
 end