New Adaptive Mesh Refinement Indicators in CTH for Detonation and Shock Waves

The Sandia-developed hydrocode CTH has used Adaptive Mesh Refinement (AMR) for over 20

years [1]. It has proven valuable for solving problems with large spatial and/or temporal scales

of interest. In some cases, AMR is the only tractable way to get an accurate solution compared

to a constant mesh spacing approach. AMR can be useful for resolving small scale shock fronts

or detonation waves being propagated, but it can be difficult to prevent the expanded region

behind the wave from being unrefined too aggressively. This unrefinement of the mesh

introduces unphysical numerical errors into the problem and can result in incorrect pressure

loading or other issues. New AMR indicators that control the rate at which the mesh can be

unrefined have been implemented into CTH. Usage of these indicators will be demonstrated

along with solution comparisons to not using the new indicators.

[1] Crawford, David. Adaptive Mesh Refinement in CTH. 15th US Army Symposium on Solid Mechanics;

Myrtle Beach, SC. 1999.