A COMPARISON BETWEEN ONE-EQUATION AND 2-EQUATION DIFFERENTIAL MODELS OF TURBULENCE IN APPLICATION TO SEPARATED AND ATTACHED FLOWS - FLOW INCHANNELS WITH COUNTERSTEP

A comparative numerical study was performed of three differential turb ulence models based on one [1, 2] and two [3] transport equations for the calculation of flows in channels with a backward facing counter-st ep. Such flows present a typical example of flows with separation and attachment. The specific features of the models under study were analy zed on the basis of comparison between the computational results and t he experimental data [4-6]. The comparison was performed in a wide ran ge of Reynolds numbers, for different step heights, and for different angles of inclination of the channel wall opposite the step. The compu tational results were also compared with those obtained from the k-eps ilon turbulence model for low Reynolds numbers [7]. It has been found that the one-equation models [1, 2], being more economical, are only s lightly less accurate than the two-equation model [3] and much more ac curate than the k-epsilon model [7].