Enhancement of heat transfer in turbulent separated and reattaching flow by local forcing

Abstract

A numerical study was made of heat transfer in locally forced turbulent separated and reattaching flow over a backward-facing step. The local forcing was given to the flow by means of a sinusoidally oscillating jet from a separation line. The Rhee and Sung version of the unsteady k - epsilon --f(mu) model and the diffusivity tensor heat transfer model were employed. The Reynolds number was fixed at Re-H = 33,000 and the forcing frequency was varied in the range 0 less than or equal to fH / U-infinity less than or equal to 2. The condition of constant heat flux was imposed at the bottom wall. The predicted results were compared and validated with the experimental data of Chun and Sung and Vogel and Eaton. The enhancement of heat transfer in turbulent separated and reattaching flow by local forcing was evaluated and analyzed.