Mr. Bate et A. Burkert, RESOLUTION REQUIREMENTS FOR SMOOTHED PARTICLE HYDRODYNAMICS CALCULATIONS WITH SELF-GRAVITY, Monthly Notices of the Royal Astronomical Society, 288(4), 1997, pp. 1060-1072
We determine a new resolution requirement for the smoothed particle hy
drodynamics (SPH) numerical method when self-gravity is included, Comp
arison calculations between an SPH code and an Eulerian grid code are
performed. The calculations are of a computationally demanding molecul
ar cloud collapse and fragmentation problem. We demonstrate that the r
esults given by the two different hydrodynamic methods are in good agr
eement, so long as the minimum resolvable mass in the SPH calculations
is always less than the Jeans mass, If this criterion is not satisfie
d. SPH may give incorrect results, with the stability of near-Jeans-ma
ss clumps depending on the details of how the SPH code is implemented
rather than on physical processes, We give examples, from the literatu
re, of problems that have been encountered in simulations of star, gal
axy and cosmological-structure formation where this resolution require
ment is ignored.