Artificial Damping for Shock Waves

Quadratic bulk viscosity q_a and linear bulk viscosity q_b are, by default, set to values relevant for hydrodynamics and high speed impact problems involving shock waves.

For fluid dynamics and acoustics, these coefficients are not required, and most generally set to very small values to override the default.

If the /CAA option is used, the default values are automatically set to very small values.