Consider the following code:
Clear[x, t, xMin, xMax, TMax, yMin, yMax];
TMax = 3.73; xMin = -Sqrt[2] Pi; xMax = -xMin; yMin = -Sqrt[
2] Pi; yMax = -yMin;
eqn = D[h[t, x, y],
t] == -Div[Grad[h[t, x, y], {x, y}]/h[t, x, y], {x, y}] -
Div[Grad[Laplacian[h[t, x, y], {x, y}], {x, y}]*h[t, x, y]^3, {x,
y}];
bcs = {h[0, x, y] == 1 - 0.1 Cos[Sqrt[2]/2*Sqrt[x^2 + y^2]],
h[t, x, yMin] == h[t, x, yMax], h[t, xMin, y] == h[t, xMax, y]};
hsol = NDSolveValue[{eqn, bcs},
h[t, x, y], {t, 0, TMax}, {x, xMin, xMax}, {y, yMin, yMax}]
The above code can be run but show no results when I try to plot it using Plot3D,like: Plot3D[hsol[0, x, y], {x, xMin, xMax}, {y, yMin, yMax}, PlotRange -> All]. Does anyone can help me with this? Thanks a lot.