  In this paper, the Entropically Damped Artificial Compressibility (EDAC)
formulation of Clausen (2013) is used in the context of the Smoothed Particle
Hydrodynamics (SPH) method for the simulation of incompressible fluids.
Traditionally, weakly-compressible SPH (WCSPH) formulations have employed
artificial compressiblity to simulate incompressible fluids. EDAC is an
alternative to the artificial compressiblity scheme wherein a pressure
evolution equation is solved in lieu of coupling the fluid density to the
pressure by an equation of state. The method is explicit and is easy to
incorporate into existing SPH solvers using the WCSPH formulation. This is
demonstrated by coupling the EDAC scheme with the recently proposed Transport
Velocity Formulation (TVF) of Adami et al. (2013). The method works for both
internal flows and for flows with a free surface (a drawback of the TVF
scheme). Several benchmark problems are considered to evaluate the proposed
scheme and it is found that the EDAC scheme gives results that are as good or
sometimes better than those produced by the TVF or standard WCSPH. The scheme
is robust and produces smooth pressure distributions and does not require the
use of an artificial viscosity in the momentum equation although using some
artificial viscosity is beneficial.
