Numerical prediction of air flow in a sharp 90 degree elbow

Abstract

Numerical and experimental investigations of turbulent air flows inside a sharp 90° elbow bend were conducted in an open-circuit horizontal-to-vertical suction wind tunnel system. Computational fluid dynamics simulations were performed using Fluent software with 3D, steady, turbulent and incompressible flow conditions assumed. Three different turbulence models were used namely the k-ε realizable, the k-ε RNG and the Reynolds Stress models in conjunction with non-equilibrium wall functions. 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). Reasonable agreement was obtained. Reynolds Stress Model was expected to perform the best; however this was not confirmed from the results.