Astronomy and Astrophysics – Astrophysics
Scientific paper
Mar 2007
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2007a%26a...464..447a&link_type=abstract
Astronomy and Astrophysics, Volume 464, Issue 2, March III 2007, pp.447-450
Astronomy and Astrophysics
Astrophysics
13
Hydrodynamics, Methods: Numerical, Stars: Oscillations
Scientific paper
Context: There is a need to improve the fidelity of SPH simulations of self-gravitating gas dynamics. Aims: We remind users of SPH that, if smoothing lengths are adjusted so as to keep the number of neighbours, N, in the range NNEIB±ΔNNEIB, the tolerance, ΔNNEIB, should be set to zero, as first noted by Nelson & Papaloizou. We point out that this is a very straightforward and computationally inexpensive constraint to implement. Methods: We demonstrate this by simulating acoustic oscillations of a self-gravitating isentropic monatomic gas-sphere (cf. Lucy), using NTOT˜6000 particles and NNEIB=50. Results: We show that there is a marked reduction in the rates of numerical dissipation and diffusion as ΔNNEIB is reduced from 10 to zero. Moreover this reduction incurs a very small computational overhead. Conclusions: .We propose that this should become a standard test for codes used in simulating star formation. It is a highly relevant test, because pressure waves generated by the switch from approximate isothermality to approximate adiabaticity play a critical role in the fragmentation of collapsing prestellar cores. Since many SPH simulations in the literature use NNEIB=50 and ΔNNEIB≥10, their results must be viewed with caution.
Attwood R. E.
Goodwin Simon P.
Whitworth Anthony P.
No associations
LandOfFree
Adaptive smoothing lengths in SPH does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Adaptive smoothing lengths in SPH, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Adaptive smoothing lengths in SPH will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-856693