Analysis of mixing enhancement ability of bypass dual throat nozzle with single/multi-tabs

Abstract

Bypass dual throat nozzle (BDTN) represents an innovative fluidic thrust vectoring nozzle capable of adjusting thrust vectoring angles through self-adaptive flow control. This study explores the BDTN-single/multi-tabs configurations, ensuring that the nozzle’s outlet projected area remains constant while introducing one or more pairs of tabs coplanar with the convergent section of the cavity. This design accounts for aerodynamic performance, thrust vectoring capabilities, and mixing abilities of the BDTN. Through theoretical analysis, design implementation, numerical simulations, and wind tunnel experiments, findings reveal that, in the case of BDTN-single-tab configuration, an increase in tab angle (α) leads to heightened streamwise vortex intensity at the nozzle outlet, reduced high-temperature core area, and enhanced jet centerline velocity and temperature attenuation rate. BDTN-single-tab achieves up to a 90% reduction in centerline-temperature/velocity decay rate, implying stronger mixing enhancement with higher tab angles. Compared to α = 10° BDTN-single-tab, the area of the high-temperature core area decays by 75%. For the BDTN-multi-tab configuration, an increase in the number of tabs results in increased thrust coefficient and vectoring angle, alongside diminished streamwise vortex strength at the nozzle outlet, and a more complex streamwise vortex structure. However, the jet’s centerline velocity and temperature decay rate decreased as a consequence.