Numerical prediction of locally forced turbulent separated and reattachingflow

An unsteady numerical simulation was performed for locally forced separated and reattaching flow over a backward-facing step. The local forcing was gi ven to the separated and reattaching flow by means of a sinusoidally oscill ating jet from a separation line. A version of the k-epsilon-f(mu), model w as employed, in which the near-wall behavior without reference to distance and the nonequilibrium effect in the recirculation region were incorporated . The Reynolds number based on the step height (H) was fixed at Re-H = 33 0 00, and the forcing frequency was varied in the range 0 less than or equal to St(H) less than or equal to 2. The predicted results were compared and v alidated with the experimental data of Chun and Sung (1996,1998). It was sh own that the unsteady locally forced separated and reattaching flows are pr edicted reasonably well with the k-epsilon-f(mu) model. To characterize the large-scale vortex evolution due to the local forcing, numerical flow visu alizations were carried out. (C) 2000 The Japan Society of Fluid Mechanics and Elsevier Science B.V. All rights reserved.