MEASUREMENT AND MODELING OF HEATING IN GAPS IN HYPERSONIC VEHICLES

A computational fluid dynamics laminar-to-turbulence transition model was developed for the NASA Ames Research Center’s 20 MW Panel Test Facility (PTF). Surface pressure, heat flux to a water-cooled plate, and surface temperature on a tile plate coated with reaction-cured glass were measured across several conditions in the facility and compared with laminar and fully-turbulent computational fluid dynamics simulations. The potential for bypass transition in the PTF nozzle was assessed via application of a correlation-based laminar-to-transition model. Results from this model were inconsistent with measurements. A boundary conditioning plate feature inside the PTF nozzle was also investigated as a potential cause of laminar-to-turbulent transition using two simplified transition models. The Baldwin-Lomax turbulence model was configured to simulate a transition at the upstream edge of the boundary conditioning plate and produced results consistent with the surface pressure measurements but not the cold-wall heat flux. Finally, a Shear Stress Transport (SST) turbulence model was calibrated to transition at the upstream edge of the boundary conditioning plate and produced results consistent with both the surface pressure and cold-wall heat flux measurements. The SST-based model demonstrated reasonable agreement with surface temperature measurements along the centerline of the reaction-cured glass tile. However, the model results qualitatively disagreed with infrared surface temperature measurements at the outboard regions of the tile.