Spatial correlation of pressure fluctuations on a plate before a step in a supersonic flow

Spatial correlation of the spectral components of the field of wall pressure fluctuations observed in a supersonic flow before a step is studied. The study is based on the results of parametric experimental measurements performed on a plate in a low-turbulence supersonic wind tunnel with a low level of acoustic noise. The roles of the Mach and Reynolds numbers and the dimensionless step height in the spatial correlation of the wail pressure fluctuations both along the flow and across it are determined. A number of specific features of the field of pressure fluctuations is revealed; these features give some insight into the held's physical nature.