Experimental evaluation of an intermittency correlation for Reynolds-averaged Navier–Stokes hypersonic boundary layer transition modeling

Measurements of a transitional boundary layer on a hollow-cylinder model in Mach 7 flow are used to evaluate a recently developed Reynolds-averaged Navier–Stokes compatible intermittency correlation for hypersonic transitional boundary layers. The Vogel–Choudhari data-driven model developed by the National Aeronautics and Space Administration Langley is assessed using experimental results from femtosecond electronic excitation tagging velocimetry, focused laser differential interferometry, schlieren imaging, and infrared thermography. Computational results using the UNstructured PArallel Compressible solver with the Vogel–Choudhari intermittency model show excellent agreement in velocity profiles, subsequent skin-friction, and surface heat flux in the laminar and turbulent regions. Discrepancies in the transitional region were seen across the various diagnostics correlating with movement of peak low-frequency fluctuations downward through the boundary layer. Overall, the intermittency model is found to perform reasonably well for the canonical flow-field, and downstream agreement in shape factor values and convergent log-law profiles shows promise for future use of the model. Additionally, the measurements are one of the most comprehensive off-body datasets to date for a hypersonic transitional boundary layer.