{ MESH_DENSITY.PDE }
{
This problem demonstrates the use of the MESH_DENSITY parameter to
control mesh density.
A global density function is defined as a Gaussian distribution returning
1 cell-per-unit density at the center, rising to 54.6 cell-per-unit density
at the corners.
This global distribution is overridden by a regional definition of 50 cell-per-unit
density in a central region.
}
title 'Cell Size Control'
Variables
u
definitions
k = 1
u0 = 1-x^2-y^2
s = 2*3/4+5*2/4
mesh_density = exp(2*(x^2+y^2))
box = 0.1
equations
div(K*grad(u)) +s = 0
boundaries
Region 1
start(-1,-1)
value(u)=u0
line to (1,-1) to (1,1) to (-1,1) to close
Region 2
mesh_density = 50
start(-box,-box)
line to (box,-box) to (box,box) to (-box,box) to close
plots
grid(x,y)
contour(u)
end