How to set up different characteristic lengths for nested cylinders
Hi,
I'm trying to create 3d mesh of nested cylinders with different characteristic lengths for each layer:
SetFactory("OpenCASCADE");
lcar1 = 1.;
lcar2 = 1.;
lcar3 = 0.2;
lcar4 = 1.;
//+
Cylinder(1) = {0, 0, 0, 20, 0, 0, 2.4, 2*Pi};
Cylinder(2) = {0, 0, 0, 20, 0, 0, 2.3, 2*Pi};
BooleanDifference(3) = { Volume{1}; Delete; }{ Volume{2};};
Cylinder(4) = {0, 0, 0, 20, 0, 0, 2.0, 2*Pi};
BooleanDifference(5) = { Volume{2}; Delete; }{ Volume{4};};
Cylinder(6) = {0, 0, 0, 20, 0, 0, 0.7, 2*Pi};
BooleanDifference(7) = { Volume{4}; Delete; }{ Volume{6};};
//+
Characteristic Length { PointsOf { Volume{3}; } } = lcar1;
Physical Volume(8) = {3};
//+
Characteristic Length { PointsOf { Volume{5}; } } = lcar2;
Physical Volume(9) = {5};
//+
Physical Volume(11) = {6};
Characteristic Length { PointsOf { Volume{6}; } } = lcar4;
//+
Characteristic Length { PointsOf { Volume{7}; } } = lcar3;
Physical Volume(10) = {7};
The problem is that in the resulting mesh the smallest cylinder has the same lcar than the next layer. even though lcar4 < lcar3:
How can I increase the characteristic length of the smallest cylinder without increasing the characteristic length of the next layer? Thank you in advance for your help.