Volume change and energy exchange: How they affect symmetry in the Noh problem

The edge viscosity of Caramana, Shashkov and Whalen is known to fail on the Noh problem in an initially rectangular grid. We present a simple change that significantly improves the behavior in that case. We also show that added energy exchange between cells improves the symmetry of both edge viscosity and the tensor viscosity of Campbell and Shashkov. As suggested by Noh, this addition also reduces the wall heating effect.