Modified Spectral Method of Anisotropic Turbulent Velocity Field Generation Preserving Incompressibility

Abstract

. A method for the numerical generation of anisotropic turbulent velocity fields is presented. The proposed technique is based on the spectral method (SM) [1]. The traditional adaptation of isotropic field generated with spectral methods uses a Cholesky decomposition of Reynolds stresses tensor. After this adaptation the resulted field loses the property of incompressibility provided in the isotropic case. We have modified this method to use it in the anisotropic case and guarantee the incompressibility of generated turbulent field. Comparison of the results of IDDES simulation of canonical turbulent flow using inlet boundary conditions based on modified and non modified spectral methods are presented.