<< Click to Display Table of Contents >> Navigation:  Sample Problems > Usage > Mesh_Control > boundary_density

{  BOUNDARY_DENSITY.PDE  

 

  This problem demonstrates the use of the MESH_DENSITY parameter to

  control mesh density along a boundary.

  The boundary of the inner region is forced to a grid spacing of 0.02

 

}

 

title 'Cell Size Control'

 

variables

    u

 

definitions

    k = 1

    u0 = 1-x^2-y^2

    s = 2*3/4+5*2/4

    b = 0.1

    c = 0.02

 

equations

   U: 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

      start(-b,-b)

      mesh_density = 1/c   { command inside the boundary path }

      line to (b,-b) to (b,b) to (-b,b) to close

 

plots

    grid(x,y)

    contour(u) on region 2

 

end