On the Reliability of Reynolds-averaged Navier Stokes Prediction of Mean Flow Characteristics of a Rectangular Turbulent Jet in Crossflow

A jet of fluid discharging into a cross stream, also known as Jet In Crossflow (JICF), has received many experimental and numerical investigations. In addition to the fundamental understanding of threedimensional mixing and shear flow characteristics, the fluid dynamics research community often regarded it as a benchmark test case for validating turbulence models. Although many authors considered the canonical case of a jet issuing from a circular orifice, the rectangular shape has received less numerical investigations. The present study deals with a jet issuing from a rectangular duct into a confined crossflow domain in which five jet-to-crossflow velocity ratios ranging from 3.3 to 10 are considered. The analysis focuses on the reliability of three two-equation turbulence models, namely k-ε, k-ω and SST in predicting this type of complex flow phenomena. Comparisons with previous large-eddy simulation results and available test data for the same problem have revealed good agreement in predicting ‘mean’ flow properties, but relative poor agreement in predicting the second-order statistics. It indicates that this type of flow exhibits significant non-equilibrium behavior for which the commonly used two-equation turbulence models are unable to deal with. Thus it is necessary to apply anisotropic turbulence model such as Reynolds stress model or high-fidelity large-eddy simulation method.