Computational Studies of Flows in the RAE 2129 S-shaped Diffusing Duct

摘要

Computational studies of the turbulent flow characteristics in an S-shaped diffusing duct had been conducted and the solutions were compared with measurements. Two different numerical approaches were used which included solving a parabolised form of the Navier-Stokes quations and the full navier-Stokes equations. In both cases, two different algebraic mixing length turbulence models with different wall damping functions were used. The duct geometry under investigation is a scaled model of the RAE 2129 (0.3 x Length offset) S-shaped intake duct for jet aircraft measured previously by Whitelaw and Yu (1993). The computed results for both cases indicated a delay on the onset of the streamwise separation region as compared to the measurements and, as a consequence, the exit mean flow distortion was found to be less severe as in the measurements. Different types of wall damping function based on those of Launder and Priddin (1972) were tested and the results were assessed.