Effects of Curvature on Two-Dimensional Diffuser Flow

The effects of curvature on diffusers have been studied experimentally and analytically. Measurements of wall pressures and boundary layer velocities have been made in three test diffusers of zero or mild curvature, in which the flow is not separated. The straight diffuser results were in very good accord with the results of flow calculations based on the Stanitz and Moses methods for treating the potential core and boundary layer regions, respectively. The curved diffuser flow measurements indicated pronounced effects of curvature on pressure and velocity distributions. Effects of curvature on boundary layers are ascribed to shear stress modification, and shown to be roughly predictable using a linear mixing length – Richardson number correlation.