脉冲放电等离子体激励在超声速气流中的时空演化特性及其调控激波串的机理

Pulsed discharge plasma excitation has the advantages of large excitation intensity, wide range of action and adjustable excitation parameters, which has broad application prospects in the supersonic complex flow control. Scramjet technology is one of the key technologies for achieving air-breathing hypersonic flight. Shock-train oscillations in the isolator of a scramjet engine can cause unstable combustion and reduced aircraft performance. By using high-spatio-temporal resolution test system and direct numerical simulation method, the spatio-temporal evolution of pulsed discharge plasma excitation in supersonic flow will be studied. The electrical characteristics, plasma characteristics and flow characteristics of the plasma excitation in the supersonic flow would be obtained. The coupling mechanism of the discharge plasma excitation and the supersonic flow is revealed and the plasma excitation system is optimized. Based on the optimized plasma excitation system, the wind tunnel experiment and numerical simulation method are used to study the oscillation of the shock train of the plasma excitation and control section. The pulsating frequency of the separation zone and the oscillation frequency of the shock train are tuned by the adjustable frequency of the plasma excitation to control the shock train. This lays the foundation for the development of high-intensity, large-area multi-channel pulsed discharge plasma excitation methods and aerodynamic design of the hypersonic vehicle technology.

脉冲放电等离子体激励具有激励强度大、作用范围广和激励参数可调等优点，在超声速复杂流动控制方面具有广阔的应用前景。超燃冲压发动机技术是实现吸气式高超声速飞行的关键技术之一。超燃冲压发动机隔离段内的激波串振荡现象，会造成发动机燃烧不稳定和飞行器性能降低。通过高时空分辨测试和高精度数值模拟，开展脉冲放电等离子体激励在超声速气流中的时空演化研究，获得等离子体激励的在超声速气流中的电学特性、等离子体特性和流动特性，揭示脉冲放电等离子体激励与超声速气流的耦合机制，并优化等离子体激励系统。基于优化的等离子体激励系统，通过风洞实验和数值仿真手段，开展等离子体激励调控隔离段激波串振荡流动的研究。基于等离子体的快响应、宽频带特性，调谐分离区脉动频率和激波串振荡频率，揭示等离子体激励调控激波串振荡流动的机理。研究成果将为高强度、大面积的脉冲放电等离子体激励方法和高超声速飞行器气动设计技术的发展奠定基础。

脉冲放电等离子体激励具有激励强度大、作用范围广和激励参数可调等优点，在超声速复杂流动控制方面具有广阔的应用前景。超燃冲压发动机技术是实现吸气式高超声速飞行的关键技术之一。超燃冲压发动机隔离段内的激波串振荡现象，会造成发动机燃烧不稳定和飞行器性能降低。通过采用高时空分辨测试系统和数值模拟方法，开展了脉冲放电等离子体激励在静止环境和超声速气流中的时空演化研究，获得了等离子体激励的的电学特性和流动特性，揭示了脉冲放电等离子体激励与超声速气流的耦合机制。通过风洞实验和数值仿真手段，开展了等离子体激励调控隔离段激波串流动的研究。利用等离子体激励的可调频率，调谐激波串振荡频率，揭示了等离子体激励调控激波串流动的机理。这为高强度、大面积的多路脉冲放电等离子体激励方法和高超声速飞行器技术的发展奠定基础。