Simulation of an Impinging Jest in a Crossflow using a Reynolds Stress Transport Model

An impinging jet in a crossflow is a flow case representative of a jet-lift aircraft operating in ground effect. Accurate modelling of this flow field is essential in predicting the practical flow problems associated with these aircraft; in particular the ingestion of hot gas into the engine intakes, and the importance of the ground vortex contribution towards this. This paper describes a numerical study of this flow using the Reynolds averaged NavierStokes (RANS) approach with a Reynolds stress transport model (RSM), validating the current results against experimental data and comparing with other numerical results. A grid-independent solution was determined and the importance of correct inlet geometry modelling demonstrated. Although slight improvements over the eddy-viscosity approach are produced, the RSM model fails to predict the correct ground vortex centre location, and vortex attachment to the impinging jet, demonstrating that the RANS approach used to solve a highly unsteady, time-dependent phenomenon is likely to result in the poor predictions seen. Therefore although the current approach does offer advantages over the k model, it still may only be suitable for gross flow-field approximations, as part of preliminary studies. For more accurate investigation of configuration-dependent effects, further investigation into the LES approach is recommended