Hysteretic behaviors in shock-induced thrust vector control

The hysteresis in the shock-induced thrust vector nozzle is investigated in the present study by manipulating the pressure at both the primary and secondary inlets. Employed pressure control functions are linear, sine, and cosine, respectively. Computational results demonstrate that the static pressure on the monitored upper nozzle wall exhibits evident hysteresis under different pressure transformations governed by these functions. Furthermore, regular reflection and Mach reflection do not instantaneously alter with variations in inlet pressure but require a certain period or range of hysteresis to complete their transformation; correspondingly, thrust vector performance also displays hysteretic behaviors. These findings indicate that unstable positive feedback effects of wall shear stress contribute to the observed hysteresis. Additionally, numerical simulations were conducted to investigate the hysteresis effects of Mach contour and vortex within the internal flow field. In summary, studying hysteresis characteristics and their formation mechanism holds significant importance for enhancing control accuracy in shock-induced thrust vector nozzles.