This is the version of Pressure-Energy SPH that includes the Morris & Monaghan (1997) variable artificial viscosity with a Balsara switch.
This should not contain too many changes in the central code. The hydro test suite is currently running but we see marginally improved convergence, see below for the 3D Gresho Vortex.
Morris, J. P., & Monaghan, J. J. (1997). A Switch to Reduce SPH Viscosity. Journal of Computational Physics, 136(1), 41–50. http://doi.org/10.1006/jcph.1997.5690