Back to Volume
Paper: The Dangers of Constraining the Kernel Radius in SPH Galaxy Simulations
Volume: 275, Disks of Galaxies: Kinematics, Dynamics and Perturbations
Page: 452
Authors: Williams, P. R.; Churches, D. K.; Nelson, A. H.
Abstract: The Smoothed Particle Hydrodynamics (SPH) method involves calculating hydrodynamic quantities in a fluid by evaluating weighted summations over particles in the vicinity of the point of interest. The characteristic resolution length over which these summations are evaluated is the so--called kernel radius h. In many SPH simulations of galaxy formation a lower limit is imposed on h equal to the gravitational softening length ε, while ε is held constant. Such a constraint limits the maximum density resolvable in a simulation, and thus indirectly provides a lower limit on the timestep. However, it has been found that such a constraint can compromise the spatial resolution to which hydrodynamical quantities are evaluated to the extent that the evolution of the gross features of resultant numerical galaxies are affected, and the ability to capture shocks vastly reduced.
Back to Volume