Study of the vortex structure of a subsonic jet in an axisymmetric transonic nozzle

Abstract

The jet interaction flow field generated by a subsonic circular jet exhausting into a transonic cross-flow over a convergent–divergent nozzle is investigated using numerical simulations. The simulations use the three-dimensional large eddy simulation and Reynolds-averaged Navier–Stokes equations coupled with the standard k-ε turbulence model. The numerical method is verified via cold-flow and schlieren experiments. The vortex structures are identified via the Liutex–Omega method, and the flow details of various pressure ratios and injection angles are studied. The numerical results capture the main vortex structures of a jet in cross-flow, such as the trailing upper vortex and trailing major vortex. The trailing top vortex, which is difficult to capture, and a new vortex structure, named the longitudinal shear vortex, are both observed when the momentum flux is sufficiently large. This study identifies the longitudinal shear vortex for restricted flow, which to some extent facilitates the mixing of the cross-flow and the jet. The results presented in this paper indicate that the vortex structure distribution of a subsonic jet and transonic cross-flow in the restricted region can be optimized. The main vortex structures are analyzed in detail.

Numerical Study on Rod Thrust Vector Control for Physical Applications

“…The flow separations in a supersonic freestream are always accompanied by various shocks that cause significant adverse pressure gradients on the boundary layer. The shock-wave/boundary-layer interaction principle plays an important role in these complex flow separations, which is strongly linked to low-frequency oscillations of separation shocks [33,34]. Figure 2 depicts the schematic of flow phenomena in a supersonic nozzle with a rod inserted through the nozzle top wall.…”

Study on the Effect of Oxidative Jet and Vortex Structure in Fluidic Throat Combined with Thrust Vector Control

“…This technology exhibits high reliability and has no drive mechanism. The concept has been successfully applied to liquid rocket motors, aeroengines, and solid rocket motors [1,9,10]. The thrust magnitude and direction can be simultaneously controlled by injecting secondary flow into the nozzle throat and divergence section [9].…”

“…The primary flow causes the jet to bend and deflect, producing intricate vortex structures. Presently, research on shock vector control (SVC) and fluidic nozzle throat (FNT) technology primarily focuses on engineering applications, but there is a lack of research on the underlying flow mechanism [10].…”