Evaluation of weakly compressible SPH variants using derived analytical solutions of Taylor-Couette flows

Abstract

Smoothed particle hydrodynamics (SPH) is a relatively young meshless particle method used in fluid simulation. The method has not yet reached a mature state and still is in the need of rigorous evaluation tests that contribute to its consolidation as a reliable numerical method. With this need in mind, the first portion of this article is dedicated to presenting a new set of validation tests. The tests consist of different types of planar Taylor?Couette flows which will be equipped with their corresponding Navier?Stokes equations? analytical solutions. Analytical solutions have been found for compressible and weakly-compressible (WC) regimes. The second part of this article is dedicated to using the obtained solutions as evaluation tests of a WC-SPH variant based on the divergence form of the Navier?Stokes equations and on the simultaneous use of different kernels. The proposed variant is compared to other previous WC-SPH variants commonly used in the literature. Velocities as well as pressure profiles can be compared with the provided analytical solutions. The performed numerical experiments show that, although all the tested WC-SPH variants match quite correctly the theoretical velocity profile, the previous variants present highly noisy pressure profiles or even give erroneous pressure solutions. Among the evaluated WC-SPH formulations, the proposed variant does a better job in matching, both, velocity profiles and pressure profiles with much lower levels of noise.