A Flow Analysis for a Turning Rapid Contraction using CFD

Abstract

Following the development of the turning rapid diffuser using CFD analyses in 2006, another analysis is carried out for a turning rapid contraction as required in the design process for wind tunnels. This is similar to the benchmark problem investigated at the 1994 annual meeting of the World User Association in Applied Computational Fluid Dynamics for the turbulent flow in an axi-symmetric 180° narrowing bend. However, the present investigation is three dimensional with rectangular cross-sections. A parametric investigation using ANSYS CFX 10 has found that the flow is mostly attached to the sidewalls of the contraction, which does not use any guide vanes. Therefore the use of turning rapid contraction concept in the design of close circuit wind tunnels would be more cost effective, in terms of flow quality and fan power requirements, than the use of traditional turning vanes in the wind tunnel circuit bends.