Minimal (Density-Energy) SPH
This scheme is a textbook implementation of Density-Energy SPH, and can be used as a pedagogical example. It also implements a Monaghan AV scheme with a Balsara switch, like the GADGET-2 scheme. It uses very similar equations, but differs in implementation details; namely it tracks the internal energy (u) as the thermodynamic variable, rather than entropy (A). To use the minimal scheme, use
As it uses a very simple, fixed artificial viscosity, only the
SPH:viscosity_alpha parameter has any effect for this scheme. This will
change the strength of the artificial viscosity throughout the simulation,
and has a default of 0.8.