Plasma plume expansion induced during laser ablation

Hello,

We are trying are to set up a model to study plasma plume expansion induced during pulsed laser deposition. Model is based on compressible Navier stokes equations consisting of mass, momentum and energy conservation. We are using equation based module of COMSOL (PDEs interface). We have implemented these equations of plasma plume into COMSOL and due to some reason it is not converging.
Can anyone assistance in this regards. Thank you.

Saba