Three-dimensional internal flow characteristics of bypass shock-induced thrust vector control

Abstract

In the current article, the computational fluid dynamics methodology by solving Reynolds-averaged Navier-Stokes equations is used to investigate the controllability and accuracy of a three-dimensional bypass shock-induced thrust vector control system, featuring an arc-shaped mass flow bypass with an active control function. Several blockage area ratios on the bypass channel have been analyzed to illustrate the control performance of the bypass shock-induced thrust vector nozzle, where they are 0, 0.05, 0.06, 0.3, 0.6, and 0.9, respectively. The computational results indicate that the flow choking in the arc-shaped bypass occurs at both its outlet and bypass throat for various blockage area ratios; furthermore, with an increasing blockage area ratio, the vectoring angle and the bypass mass flow ratio decrease continuously. While the blockage area ratio is constant, both the thrust ratio and specific impulse coefficient rise with the increasing nozzle pressure ratio; however, the deflection angle and thrust efficiency constantly decrease. A smaller nozzle pressure ratio corresponds to a larger vectoring angle. Significant Mach disc forms, as the convergent-divergent nozzle is under severe over-expanded conditions. Both the blockage area ratio and nozzle pressure ratio are fixed, and the bypass mass flow ratio increases linearly with the increase of the bypass width ratio, resulting in a gradual increase in the vectoring angle; meanwhile, the thrust efficiency, thrust ratio, and specific impulse coefficient gradually decrease.