Optimization of Inlet Swirl for Flow Separation in Annular Diffuser

Abstract

The flow development characteristics and its performance have been studied with the help of computational fluid dynamics with various inlet swirl angle inside the parallel hub axial annular diffuser having an equivalent cone angle 15° for area ratio 2. The analysis predicts the effect on Non-dimensional velocity profile, streamline velocity, static pressure recovery on the casing wall, and reversal of flow on the diverging part of the diffuser. To predict the optimum inlet swirl angle encounters the optimum performance with no flow separation either on hub or casing wall. The results reveal that increasing the inlet swirl angle leads to distortion of the longitudinal velocity profile at the diffuser exit.