SimpleFoam: Laminar vs. Turbulent Convergence
 

I have been experimenting with some test cases for internally bounded flow of a control valve manifold. Based on the geometry of certain passages, I have assumed that under a certain flow rate the flow regime should be laminar throughout the volume and turbulent above that value.

Utilizing the same mesh for all cases, I have successfully run the turbulent model (k-epsilon) on a test case that should yield turbulent flow in most regions. I have also successfully run the laminar model on a test case that should yield laminar flow in most regions. When I attempt to use the turbulent solver on the same laminar test case I start to get convergence then the solution crashes on me. I was initially thinking that the turbulent solver could be applied towards a laminar case, and the k,e, & nut variables would have a negligible contribution to the result. Is this an erroneous assumption, or is there possibly some other issues going on?

Just before the solver crashes, the two cases have a 0.9 psi difference in results.