nHD is a multi-GPU 2nd order full Godunov three-dimensional uniform-mesh Euler equations solver for calorically ideal, compressible gas. nHD uses CUDA C with MPI and runs on a cluster of multi-GPU machines to accelerate computational hydrodynamics calculations.

Full Godunov method solves the hydrodynamic equations by discretizing the fluid and calculating the nonlinear evolution of the discretized distribution, using the analytic solutions for Riemann problems. Thus full Godunov method can resolve arbitrary severe shockwaves with minimum artificial dissipation and oscillation, and is the irreplaceable method for simulations of compressible fluid where shockwaves and vacuums are naturally generated from fluid motions.

nHD is open source under a BSD-style license and is available, and comments are welcome at http://code.google.com/p/astro-attic/wiki/NHDIntroduction.