An investigation of shock/boundary-layer interactions on curved surfaces at transonic speeds

Abstract

A detailed experimental investigation has been made of shock/boundary-layer interactions on curved surfaces at transonic speeds. The shock waves were generated above circular-arc models with different radii mounted on the floor of the wind-tunnel test section. The ratio of the boundary-layer thickness (U/Ue = 0.99) in front of the shock to the radius of the surface curvature ranged from 0 (i.e. a flat surface) to 0.068. The Mach number just in front of the shock varied from 1.00 to 1.82 and the Reynolds number based on the model chord length was about 1.6 million. Interacting-flow studies include flows with shock-induced separation, flows with trailing-edge separation and flows with no separation. From all these studies it was found that separation was most extensive at the critical peak Mach number at which the separation changes from trailing-edge separation to shock-induced separation.

Large-eddy simulation of transonic turbulent flow over a bump

“…For many practical flows, the interaction takes place at transonic speed on a curved surface, where the turbulent boundary-layer experiences large pressure gradients. Experimental investigations of shock/turbulent-boundary-layer interaction with nonzero pressure gradients have been carried out by Delery (1983) using a variable-curvature bump geometry, and by Liu and Squire (1988) using a circular-arc bump geometry. Both studies showed significant flow changes in the transonic regime, including a k-shock pattern and extensive flow separation.…”

Effects of Surface Roughness on Turbulent Transonic Flow Over Circular Arc Bumps in a Channel

“…In the first phase of the study the performance of four different turbulence models in the computation of transonic flow over bumps with smooth surfaces is evaluated against the experimental results of Liu and Squire (1988) and Inger and Gendt (1997). From the qualitative comparison of the predicted result with the experimental data, it is observed that the Reynolds stress model produces relatively more accurate results than the other models for these types of flow.…”

“…In the experiment the shock location was controlled by an adjustable throat downstream of the bump with a corresponding adjustment of the back pressure. Since the geometrical details of this throat and corresponding back pressure are not provided by Liu and Squire (1988), the specified back/exit pressure is chosen after some trial to fit the experimental pressure distribution and shock location on the bump surface. The top wall and the wall containing the bump are solid walls having no-slip condition imposed with a constant temperature of 290 K. Further computation of the Liu and Squire (1988) case is performed with the other three remaining turbulence models and using the 220 mesh.…”

Turbulent Transonic Flow Over Smooth and Rough Circular Arc Bumps in a Freestream

“…In the earlier studies by Sharif (2005, 2009) (Wilcox, 2002), and the Reynolds stress transport model (RSM) (Launder, Reece and Rodi, 1975), in the computation of turbulent transonic flow over a smooth bump in a channel was evaluated against the experimental data of Liu and Squire (1988) and Inger and Gendt (1997). Some representative comparison of the predictions by different turbulence models against the experimental data of Liu and Squire (1988) is presented in Fig. 1.…”

“…Two types of flow configurations have been used in the published literature to investigate the transonic flow over bumps. Most of the experimental work (Liu and Squire, 1988;Barakos and Dirikakis, 1998;Inger and Gendt, 1998) and related numerical computations (Liu and Squire, 1985) have been performed for the cases where the bump is placed on one surface in a channel confined by a parallel surface matching wind tunnel configuration. In the other configuration, the bump is placed on a plane surface in a parallel freestream flow.…”