Numerical simulation for turbulence-driven secondary motion over a streamwise external corner

摘要

Numerical simulation, based on a Reynolds Stress Model (RSM), of turbulent flow over a streamwise external corner is presented. This work is an extension of an earlier experimental study (Moinuddin et al., 2004), which identified a pair of counter-rotating vortices placed around the corner of a 6 m long model. Experimental data measured at an early station is used as the inlet condition for the numerical simulation. Mean flow and turbulence statistics from numerical simulation are compared with the experimental data at a downstream station and they are found to be in excellent qualitative agreement. For the scaled mean flow data, quantitative agreement is also very good. Investigation reveals that vorticity production by secondary shear stress is dominant in generating secondary flow over an external corner, which is opposite for the case of an internal corner as found by Xu and Pollard (2001).