Published online by Cambridge University Press: 04 July 2016
In this paper the results are given of an experimental investigation into the flow development and the surface pressures in an unsteady shock boundary layer interaction at Mach numbers of 1.3 and 1.5. The experiment is one in which a naturally grown turbulent boundary layer on the tunnel walls is disturbed by a normal shock wave spanning the test section of the tunnel. The shock wave is oscillated by a periodic pressure disturbance in the tunnel diffuser far downstream of the interaction. Both instantaneous (spatially averaged) and time averaged results for the surface pressures are presented. These results are used to study the flow development and phase changes through the interaction over a frequency range from 34 to 167 Hz. This frequency range was chosen to cover the range of parameters likely to occur in conditions corresponding to stall flutter in the compressor fans of large bypass engines.
Currently DRA W7 Division, Fort Halstead and visiting fellow, College of Aeronautics, Cranfield.