We present a smoothed particle hydrodynamic model for incompressible fluids. As opposed to solving a pressure Poisson equation in order to get a divergence-free velocity field, here incompressibility is achieved by requiring as a kinematic constraint that the volume of the fluid particles is constant. We use Lagrangian multipliers to enforce this restriction. These Lagrange multipliers play the...

In this review the theory and application of Smoothed particle hydrodynamics (SPH) since its inception in 1977 are discussed. Emphasis is placed on the strengths and weaknesses, the analogy with particle dynamics and the numerous areas where SPH has been successfully applied. 0034-4885/05/081703+57$90.00 © 2005 IOP Publishing Ltd Printed in the UK 1703

We investigate the core mass distribution (CMD) resulting from numerical models of turbulent fragmentation of molecular clouds. In particular we study its dependence on the sonic rms Mach numberMs. We analyze simulations withMs ranging from 1 to 15 to show that, asMs increases, the number of cores increases as well, while their average mass decreases. This stems from the fact that high Mach num...