I would like to mesh a cylindrical fracture as follows in the picture: enter image description here
The cells in the mesh have the hexahedral form with 6 faces and 8 nodes.This mesh will be used in fipy to solve a diffusion equation.(radial flow) could anyone help in answering my question regarding the mesh using gmsh code? since it is the only way being compatible with fipy. I appreciate your help. Thank you very much.