Numerical Studies of a Two Dimensional Symmetric Diffuser in a Turbulent Flow Using CFD

Abstract

The numerical studies of a two dimensional asymmetric diffuser in turbulent flow with maximum pressure at the exit is obtained using computational fluid dynamics. The three Reynolds number based on the bulk mean velocity and the channel height at the diffuser entrance is 18000, 40,000 and 60,000. The maximum pressure is obtained to be zero skin friction along the diffuser wall. The turbulent flow inside the diffuser is predicted using three Reynolds average navier stokes based turbulence models are considered for the study i.e., K-e standard, K-e RNG and K-w SST. The designed diffuser geometry has analyzed with fluent for its design intent. The variation of static pressure, velocity, skin friction coefficient and pressure coefficient are studied for three different Reynolds numbers. The designed diffuser geometry has been used in gas turbine engine exhaust. The function of diffuser is the kinetic energy of incoming exhaust gases from the power turbines is converted into static pressure through the diffuser. It also helps in discharging of exhaust gases from high speed to low speed, and also to turn the flow of gases from axial to radial direction.