Numerical investigation of 180o curved diffuser performance by varying geometrical and operating parameters

Abstract

The geometry of a curved diffuser often inviting the flow to separate. The flow separation phenomenon plays a vital role in the recovery of pressure inside the diffuser. Besides, the geometrical and operating aspects of a curved diffuser have always been taken into consideration in most relatable researches. Pressure recovery and flow uniformity of a steady, developed entering turbulent flow of a circular-sectioned 180° curved diffuser has been investigated numerically by varying geometrical and operating parameters. The curved diffuser with area ratio (2, 3 and 4), radius of inlet and curvature of respectively 50 mm and 180 mm was considered. Different values of Reynolds number 6 × 104, 12 × 104, 18 × 104, 24 × 104, and 30 × 104 were tested in every area ratio set. ANSYS code Fluent was used to run the simulation by considering different turbulence models, i.e. the standard k-ε turbulence model (std k-ε), Spalart-Allmaras turbulence model (SA), k-kl-ω transition turbulence model and transition SST model. The present work proposed the curved diffuser with AR=2 operated at Re=6x104 as the optimum set of parameters, with minimal flow separation occurring in the system.