Zonal Detached-Eddy Simulations of a Dual-Stream Jet

Abstract

This paper presents a study using zonal detached-eddy simulation to simulate the flow of a dual-stream nozzle. The nozzle design and operating conditions are typically those of an aircraft engine at cruise, although the external flow speed is not simulated. The paper focuses on the effects on the mixing-layer development and the shock-cell positioning of a low dissipative spatial scheme, as well as the interest of a subgrid length scale based on local vorticity, in the frame of mode 1 and mode 2 of a zonal detached-eddy simulation. Reynolds-averaged data are discussed in terms of mean and fluctuating quantities. Results are compared with experimental data. The dependency on the numerical scheme is demonstrated, and the advantage of the subgrid length scale based on the local vorticity is confirmed, especially for the development of the core mixing layer, which is triggered by small velocity differences. A spectral analysis of the fluctuating aerodynamic field is performed, and the salient results concerning the physics of shear layers and the interactions between shocks and mixing layers are compared with those provided in the literature. Eventually, the “automatic” mode of the zonal detached-eddy simulation (mode 2) is investigated and is found to provide similar results to the user-defined mode.