Main Laws of the Influence of a Flow Angularity on the Parameters of Pressure Fluctuation Fields in front of a Forward-Facing Step and behind a Backward-Facing Step

摘要

Experimental investigations of the influence of flow angularity on the properties of pressure fluctuation fields in front of a forward-facing step and behind a backward-facing step are performed. These fields are shown to be inhomogeneous and three-dimensional in the case of flow angularity. It is shown that the pressure fluctuation field is characterized by the lowest scale of the inhomogeneity along the orthogonal line to the step edge, the highest degree of correlation, and the presence of convective field properties in the direction collinear to the flow. The influence of the flow angularity on the scale of the inhomogeneity and normalized mutual spectrum of pressure fluctuation fields in front of a forward-facing step and behind a backwardfacing step is reveled to a lesser degree than its influence on the spectral density. Refinement of the empirical model of the pressure fluctuation field in front of a forward-facing step and behind a backward-facing step is proposed taking into account the three-dimensionality of the field.