Hydrodynamic simulations with the Godunov SPH

摘要: We present results based on an implementation of the Godunov Smoothed Particle Hydrodynamics (GSPH), originally developed by Inutsuka (2002), in GADGET-3 hydrodynamic code. first review derivation GSPH discretization equations moment and energy conservation, starting from convolution these with interpolating kernel. The two most important aspects numerical are (a) appearance fluid velocity pressure obtained solution Riemann problem between each pair particles, (b absence artificial viscosity term. carry out three different controlled hydrodynamical three-dimensional tests, namely Sod shock tube, development Kelvin-Helmholtz instabilities a shear flow test, "blob" test describing evolution cold cloud moving against hot wind. The our tests confirm extend number those recently Cha (2010): (i) provides much improved description contact discontinuities, respect to SPH, thus avoiding spurious forces; (ii) is able follow gas-dynamical instabilities, such as Kevin--Helmholtz Rayleigh-Taylor ones; (iii) result, describes curl structures shear-flow dissolution test. We also discuss detail effect performances changing its implementation. demonstrate that fact highly promising scheme, be coupled N-body solver, for astrophysical cosmological applications. [abridged]