English

A pseudospectral method for direct numerical simulation of low-Mach, variable-density, turbulent flows

Fluid Dynamics 2022-06-22 v1 Computational Physics

Abstract

A novel algorithm for the direct numerical simulation of the variable-density, low-Mach Navier-Stokes equations extending the method of Kim, Moin, and Moser (1987) for incompressible flow is presented here. A Fourier representation is employed in the two homogeneous spatial directions and a number of discretizations can be used in the inhomogeneous direction. The momentum is decomposed into divergence- and curl-free portions which allows the momentum equations to be rewritten, removing the need to solve for the pressure. The temporal discretization is based on an explicit, segregated Runge-Kutta method and the scalar equations are reformulated to directly address the redundancy of the equation of state and the mass conservation equation. An efficient, matrix-free, iterative solution of the resulting equations allows for second-order accuracy in time and numerical stability for large density ratios, which is demonstrated for ratios up to 25.7\sim 25.7.

Keywords

Cite

@article{arxiv.2206.09878,
  title  = {A pseudospectral method for direct numerical simulation of low-Mach, variable-density, turbulent flows},
  author = {Bryan W. Reuter and Todd A. Oliver and Robert D. Moser},
  journal= {arXiv preprint arXiv:2206.09878},
  year   = {2022}
}
R2 v1 2026-06-24T11:57:29.124Z