MATLAB: How to apply a sinusoidal heat input into one of the faces of a 3-D PDE model? And how would I show the results at several different timestamps at once

Question

This is what I currently have at the moment:

model = createpde; g = importGeometry(model, 'Unit cell for MATLAB 2.stl'); pdegplot(g,'FaceLabels','on', 'FaceAlpha',0.5)

applyBoundaryCondition(model,'neumann','Face',2,'g', sin(2*tlist));

applyBoundaryCondition(model,'neumann','Face',1,'g',0);

applyBoundaryCondition(model,'neumann','Face',3,'g',0);

applyBoundaryCondition(model,'neumann','Face',5:6,'g',0);

applyBoundaryCondition(model,'dirichlet','Face',4,'u',0);

specifyCoefficients(model,'m',0,'d',1,'c',1,'a',0,'f',0);

setInitialConditions(model,300);

generateMesh(model,'Hmax',0.3);

tlist = 0:1:10;

results = solvepde(model,tlist);

u = results.NodalSolution;

pdeplot3D(model,'ColorMapData',u(:,2))

The codeline in bold corresponds to the selected face and boundary type that corresponds to it. From what I understood in my reading, the g coeff is where I need to add the sinusoidal wave function. I've tried moving up the tlist variable to the line just before the bolded code but to no avail.

Answer 1

You need to pass a nonconstant boundary condition coefficient as a function handle with the correct syntax. For your case, I would imagine that the function is @(region,state)sin(2*state.time).

Alan Weiss

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