Publications Details

Relaminarization Effects on a Three-Dimensional Cone-Slice-Ramp Geometry at Mach 8

Pandey, Anshuman; Saltzman, Ashley J.; Casper, Katya M.; Beresh, Steven J.; Bhakta, Rajkumar; Denk, Brian P.; De Zetter, Marie E.; Spillers, Russell W.

This study explores the evolution of a turbulent hypersonic boundary layer over a spanwise-finite expansion-compression geometry. The geometry is based on a slender cone with an axial slice that subjects the cone boundary layer to a favorable pressure gradient. The mean flow field was obtained from a hybrid RANS-LES computation that showed the thickening of the boundary layer, a decrease in the mean pressure and the development of incipient streamwise vortical structures on the slice. The experiments use fluctuating surface pressure and shear-stress sensors along the centerline of the slice which demonstrate significant reduction in turbulence activity on the slice indicating relaminarization of the boundary-layer. These observations were corroborated by high framerate schlieren, filtered Rayleigh scattering and scanning focused laser differential interferometry. When a 10◦ ramp is introduced at the aft end of the slice, the effectively relaminarized boundary-layer separates upstream of the slice-ramp corner due to its increased susceptibility to separation in comparison to a turbulent boundary layer.