| Shock wave/boundary layer interaction is ubiquitous in the supersonic flow field,and it is a key problem restricting the development of high-speed aircraft.Especially in scramjet engine,the shock wave/boundary layer interaction in the inlet will lead to serious performance degradation or even engine unstart.Because of its effective control function and strong robustness,micro-vortex generator has become an important content of extensive research in the world,but its control ability has limitations.Therefore,it is of great significance to explore a new control scheme and ensure its simple and stable structure.In this paper,based on the incident shock wave/boundary layer interaction problem,the control mechanism of micro-vortex generator and its combination is studied by combining numerical calculation and experimental verification.Firstly,the research results of shock wave/boundary layer interaction at home and abroad in recent ten years are summarized from the classification of time average characteristics and dynamic characteristics.The research progress of micro-vortex generator control in aircraft internal and external flow field is summarized.The new secondary recirculation control method is introduced as well,which lays a theoretical foundation for the follow-up research of this paper.Secondly,the three-dimensional RANS equations coupled with the SST K-ωturbulence model are introduced.The experimental data obtained from the published literature are verified to ensure the feasibility and accuracy of the selected numerical method for this study.The experimental platform and flow field image measurement technology used in this paper are introduced.The flow field is calibrated,and the experimental platform is adjusted according to the schlieren results.Then,the flow field structures around the micro-vortex generator and the evolution process of wake flow are studied in detail by numerical simulation.The streamwise location of micro-vortex generator in the flow field is selected to study its control effect on the shock wave/boundary layer interaction flow field at six different locations.The results show that in the flow field conditions used in this paper,when the streamwise location of the micro-vortex generator is closer to the separation zone,its control performance is better,but it inevitably leads to the increase of some heat flux.Then,based on the obtained results of Chapter 3,six kinds of combination schemes of micro-vortex generators and secondary recirculations are designed.The relative position of the micro-vortex generator and the secondary recirculations,the angle of the secondary recirculations channel,the channel quantity ratio of the micro-vortex generator and the secondary recirculations are studied respectively.Through the simulation results,the optimal control performance of the combination scheme is obtained.When the microvortex generator is placed between the bleed slot and the blow slot of secondary recirculations,and the ratio of the micro-vortex generator to the secondary recirculations is 1:2,the control of the combination is optimal.Wind tunnel experiments are carried out to verify the feasibility of the control scheme.By analyzing the transient flow structure and time correlation of the composite,the flow control characteristics in the shock wave/boundary layer interaction flow field are further studied.Finally,the flow field information of the optimal combination scheme in Chapter 4is deeply studied by using orthogonal experimental and range analysis method.The relationship between design parameters and three objective parameters,namely minimum separation bubble volume,minimum peak wall heat flow and minimum total pressure loss,is established.Three models are optimized according to the objective and verified by numerical simulations. |
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