mesh_spacing

<< Click to Display Table of Contents >>

Navigation:  Sample Problems > Usage > Mesh_Control >

mesh_spacing

Previous pageReturn to chapter overviewNext page

{ MESH_SPACING.PDE  

 

 This example demonstrates the use of the MESH_SPACING parameter to

 control mesh density.

 

 A global density function is defined as a Gaussian distribution returning  

 1 unit mesh spacing at the center, falling to 0.018 at the corners.

 

 This global distribution is overridden by a regional definition of  

 0.02 mesh spacing 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_spacing = exp(-2*(x^2+y^2))  

    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  

      mesh_spacing = c  

      start(-b,-b)    

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

 

plots  

    grid(x,y)  

    contour(u)  

 

end