Zonal detached eddy simulation of a controlled propulsive jet

This paper presents zonal detached-eddy simulation of a round underexpanded sonic jet exhausting from a realistic aircraft afterbody and controlled by four radial injections. The comparison with a former experiment proves the capability of zonal detached-eddy simulation to reproduce mean flow induced by the complex interaction between the compressible waves and the turbulent jet shear layer. However, the very near-field jet structure indicates that the shear-layer transition to a fully turbulent state is delayed. Therefore, a modification of the characteristic length scale used in the modeling is proposed which is shown to improve the prediction of the shear-layer growth. The control injectors are aimed to enhance jet mixing. Experiment indicated the efficiency of this additional device but also expressed the need for more data to get a deeper and more complete insight into the whole flowfield. Both spatial and temporal information are provided by zonal detached-eddy simulation which is then a good candidate. This method is shown to correctly simulate streamwise vortices generated by secondary injections, their action in jet distortion, as well as their subsequent decay. Finally, computational results allow us to evaluate the action of the hypermixer on turbulent activity and its consequences on jet dilution.