Reynolds-stress and dissipation-rate budgets in a turbulent channel flow

Abstract

The Budgets For The Reynolds Stresses And For The Dissipation Rate Of The Turbulence Kinetic Energy Are Computed Using Direct Simulation Data Of A Turbulent Channel Flow. The Budget Data Reveal That All The Terms In The Budget Become Important Close To The Wall. For Inhomogeneous Pressure Boundary Conditions, The Pressure—Strain Term Is Split Into A Return Term, A Rapid Term And A Stokes Term. The Stokes Term Is Important Close To The Wall. The Rapid And Return Terms Play Different Roles Depending On The Component Of The Term. A Split Of The Velocity Pressure-Gradient Term Into A Redistributive Term And A Diffusion Term Is Proposed, Which Should Be Simpler To Model. The Budget Data Are Used To Test Existing Closure Models For The Pressure—Strain Term, The Dissipation Rate, And The Transport Rate. In General, Further Work Is Needed To Improve the models.