Investigation of flow inside sharp bend elbows using numerical fluid mechanics.

Abstract

Bent pipes and ducts are used extensively in the industrial complexes mainly due to space constraints. However, bends in pipes and ducts cause pressure losses and generate flow separation inside in the pipes and ducts reducing the efficiency of fluid transport. Numerical investigations of turbulent air flows inside sharp bend elbows with different angles of bend were conducted using ANSYS FLUENT the commercially available CFD software. Computational fluid dynamics simulations were performed using FLUENT software with 2D, steady, turbulent and incompressible flow conditions assumed. Standard k-ɛ turbulence model was used to calculate turbulence quantities. The predictions of mean velocity profiles of the air flow inside the sharp 90˚ elbow duct were compared against the experimental results obtained using laser Doppler Anemometry (LDA) and other available computational studies. Reasonable agreement was obtained. The present computational study was extended to flows inside the bend elbow with bend angle ranging from 0 deg to 150 deg, from the point of view of calculating pressure loss due to the bend and to capture secondary flow characteristics in the elbow region.