Investigation of cold flow field characteristics in strut–cavity integrated afterburner

Abstract

In order to improve the structure layout and flow performance of the traditional afterburner, an integrated afterburner structure with a combination of strut and cavity is proposed in this study. The cold flow field characteristics of this strut–cavity integrated afterburner are investigated using particle image velocimetry (PIV) experiments and numerical simulations. The results indicate that the combination of struts and cavities can establish multiple stable low-speed recirculation zones under different inlet flow conditions, thereby facilitating reliable ignition and sustained combustion stability within the afterburner. In terms of overall flow performance, the total pressure recovery coefficient exhibits a progressive decrease along the axial direction, whereas the flow resistance coefficient demonstrates a corresponding increase. Furthermore, with increasing inlet velocity, the velocity gradient induced by the strut and concave cavity intensifies, leading to a reduction in the total pressure recovery coefficient and a simultaneous rise in the flow resistance coefficient at the afterburner outlet. Specifically, at an inlet velocity of 20 m/s, the outlet total pressure recovery coefficient and flow resistance coefficient are 0.9988 and 0.2561, respectively. When the inlet velocity increases to 100 m/s, these values become 0.9659 and 0.3206, respectively. These numerical results demonstrate the promising potential of the integrated afterburner configuration, particularly in terms of establishing favorable flow conditions for flame stabilization.