Hello!
I am trying to map the diffusion in a cylinder with the parameters of .25 dia / 2 length ( -1 to 1), specifically to understand the effects of removing boundary conditions and the effect this has on the simulation time to reach steady state.
Initially, I'm working with a 1-D axial diffusion set up, with insulation imposed on the cylinder length wise. All's well and good here, the solution approaches steady state in ~2,1 seconds.
Then, my objective is to do a 2-D analysis by removing the insulating boundary condition on the surface of the cylinder's length. I've tried to do this by over riding the flux condition, as well as an open boundary condition, however i am still getting 2.1 seconds to steady state, what gives?
My values for clarification - initial concentration is zero, diffusion is set to 1, and the concentrations on either end are set to 1.
Additionally, I want to make this a 3-D model by breaking symmetry along the theta direction, ie making theta vary from 0 to pi at the maximum radius. Any idea how to do this on comsol? I'm relatively new, and any help would be appreciated!
Thank you!