3D diffusion equation in cylinder

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Hi everyone, I am new in Matlab and I need some help. I want know if there is a way to solve the PDE for diffusion in a cylinder with 2 cm radius and 10 cm height.
thanks

Accepted Answer

Precise Simulation
Precise Simulation on 22 Nov 2017
Edited: Precise Simulation on 22 Nov 2017
Modelling and simulation of convection and diffusion for a 3D cylindrical (and other) domains is possible with the Matlab Finite Element FEM Toolbox , either by using the built-in GUI or as a m-script file as shown below.
% Set up 3D cylindric domain.
fea.sdim = { 'x' 'y' 'z' };
fea.grid = cylgrid( 4, 3, 20, 0.02, 0.1 );
% plotgrid( fea ) % Plot mesh.
% Add covection and diffusion physics mode.
fea = addphys( fea, @convectiondiffusion, {'C'} );
% Define diffusion coefficient.
fea.phys.cd.eqn.coef{2,end} = {'d_coef'};
fea.expr = { 'c', {'1.23'} ;
'd_coef', {'(1+c)^2/((1+c)^2+1)'} };
% Set reaction source term to 1e3.
fea.phys.cd.eqn.coef{6,end} = {1e3};
% Use C = -1 on side boundaries, and insulation
% flux boundary conditions on the top and bottom.
fea.phys.cd.bdr.sel = [ 3 1 1 1 1 3 ];
[fea.phys.cd.bdr.coef{1,end}{2:5}] = deal(-1);
% Check, parse, and solve problem with stationary solver.
fea = parsephys( fea );
fea = parseprob( fea );
fea.sol.u = solvestat( fea );
% Postprocessing.
postplot( fea, 'sliceexpr', 'C' )
title( 'Concentration, C' )
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More Answers (1)

Torsten
Torsten on 30 May 2017
If you have experience with the discretization of partial differential equations, you can write your own MATLAB code.
Otherwise, I'd suggest you use the PDE toolbox.
Best wishes
Torsten.

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