EFFECT OF CASING WALL ANGLE ON THE PERFORMANCE OF DIFFUSER

Abstract

A diffuser is a device for converting the kinetic energy of an incoming fluid into pressure. As the flow proceeds through the diffuser there is continuous retardation of the flow resulting in conversion of kinetic energy into pressure energy. Such a process is termed as diffusion. Diffuser forms an important part in flow machinery and structures. The present study involves the CFD analysis of effect of inlet swirl and casing wall angle on flow characteristics. The annular diffuser considered in the present case has both the hub and casings are diverging with equal angles and hub angle keeping constant as 5°. The geometries of all the diffusers are calculated for constant area ratio 3 and casing wall angles of 15°, 20°, and 25°. Swirl angle of 12°, 17°, 25° are introduced at the inlet. The characteristic quantities such as pressure coefficient distribution at hub and casing walls, velocity profiles at various sections and flow patterns have been presented for studying. Introd...