Title: Eliminating the residual velocity divergence of spectral methods in channel turbulence

Authors: Zehao Chen; Le Fang

Addresses: LCS, Ecole Centrale de Pékin, Beihang University, Beijing 100191, China ' LCS, Ecole Centrale de Pékin, Beihang University, Beijing 100191, China; Beihang Hangzhou Innovation Institute Yuhang, Hangzhou 310023, China

Abstract: The problem of residual velocity divergence exists in numerical simulations of channel flows which use spectral methods. The present contribution analyses the source of the residual velocity divergence, and introduce a new correction method by adding a new pressure correction substep and using ghost grids. The new method can completely eliminate the residual velocity divergence without breaking the non-slip condition. Numerical results show that the residual velocity divergence is well eliminated, while a-posteriori results are not becoming worse. We then conclude that the numerical simulations by using the present method are more close to the incompressible N-S equations, but the influence to a-posteriori statistical quantities is still worth to be investigated in the future.

Keywords: channel turbulence; Chebyshev discretisation; spectral method; residual velocity divergence.

DOI: 10.1504/PCFD.2024.138177

Progress in Computational Fluid Dynamics, An International Journal, 2024 Vol.24 No.3, pp.127 - 134

Received: 28 Aug 2021
Accepted: 27 Nov 2022
Published online: 30 Apr 2024 *

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