Mixing and film cooling in supersonic duct flows

A study for gas dynamics and heat transfer characteristics is presented for supersonic turbulent flows inside a channel of rectangular cross-section, with film cooling provided by tangential injection of coolant through the porous slots. A Navier-Stokes-based model with both original and non-equilibrium versions of the κ-ε two-equation turbulence model, and an integral method have been assessed with experimental measurements to gain insight into the fluid physics, and to assess the current predictive capability for such flows. Navier-Stokes-based computations show that the interaction between the main and film flows leads to mixing and recirculation, with the overall flow and pressure fields reasonably predicted. However, the computed temperature distribution on the adiabatic wall and pressure at the injection points exhibit noticeable differences compared to the experimental measurements. The integral method is shown to be capable of accounting for the wall temperature profile under the given flow condition and geometry. Further development of the film cooling technologies for supersonic flows can benefit from the present coordinated approach utilizing the detailed Navier-Stokes and integral models along with direct experimental evaluations. © 2002 Published by Elsevier Science Ltd