During the interpolation and restart of Natural Convection models with Mesh Adaptation, the solution can appear to have accelerated flow or become unstable.
Buoyant flow is highly sensitive to subtle differences in the density gradient. As the solution is interpolated on to the new mesh, if there is a difference between the interpolated temperature gradient and the respective density / velocity gradient, this can cause a minor flow acceleration that has the possibility of running away.
When running Natural Convection models with Mesh Adaptation, under the Flag Manager use the following flag:
This will force the solution to start from the beginning to ensure stability and accurate results for buoyant models..
Products: Simulation CFD