초록 열기/닫기 버튼
The next generation unmanned combat aerial vehicle (UCAV) has installed the stores inside to minimize detection area exposed to radars and infrared detectors. The stability of stores separation is affected by geometry of cavity and external environment. In open cavity, resonance which causes failure of store separation and fatigue is generated by disturbance of free shear layer and pressure wave. SparkJet, one of the techniques to suppress this resonance, has the advantage of supersonic flow control. In this study, the two-dimensional Navier-Stokes equation was analyzed for the cavity flow of Mach 1.5 using a meshless method, and the flow control was performed according to the injection location using a SparkJet. The time-averaged surface pressure distribution, response time, sound pressure level, and the change in the flow field were analyzed. While the time-averaged surface pressure was reduced by 8.76% when jet was injected in upstream, it was increased by 8.27% to 11.75% when jet was injected inside of cavity. The response time was faster when jet was injected at the center of trailing edge. When the SparkJet is injected near the leading edge, and center of the trailing edge the cavity flow was stabilized and the resonance was removed. The resonance was not suppressed completely when the jet was injected near the back but the strength of the pressure oscillations was found to be weakening up to 6.28dB and its frequency increased by 0.21kHz. This study provides the foundation for flow control of cavity with complex geometry, such as UCAVs.
