On the Role of Correlation Between Instantaneous Velocity and Pressure-Gradient in Large-Scale Turbulence

Abstract

Turbulent transport of Reynolds stress by triple moment of fluctuating velocity and pressure-velocity correlation are evaluated from a DNS for wake of a rectangular cylinder located in a uniform flow. The turbulent diffusion transport of turbulent kinetic energy hardly correlates with its gradient vector, indicating that the generally accepted gradient diffusion model is inadequate. It is inferred that the separate modeling of the individual Reynolds stress component provides a better possibility for modeling the turbulent transport in this flow, because of the strong departure from the equilibrium state of turbulence. The possibility of the direct modeling of the pressure gradient-velocity correlation is discussed.