高超声速边界层基于流动结构的降热减阻控制技术研究

As is well known, for the importance on the performance of hypersonic aircraft, flow control technique of drag and heat flux reduction in hypersonic boundary layer gain more and more attention, since that they are 3-5 times in the case of turbulence than that of laminar flow. Currently, most techniques used to reduce drag and heat flux in hypersonic boundary layer are developed from low speed flow, which limit the application a lot. In our early study, we found that well designed roughness element can reduce drag and heat flux obviously in hypersonic boundary layer, which shine new light on the flow control technique. However, the mechanism that roughness element reducing drag and heat flux need more study. To obtain this goal, linear stability theory, high resolution numerical simulation, as well as experiments are utilized. In the mean time, taking the flow condition, roughness element geometry scale and the position they set, we believe that both new flow control technique and the design method, based on flow structure control, on drag and heat flux reduction of hypersonic flow will be established, which will of course improve the future hypersonic aircraft design ability.

众所周知，由于湍流摩阻和热流为层流的3-5倍，降热减阻对高超声速飞行器的整体性能至关重要。当前，高超声速飞行器的减阻技术主要从低速流动中推广过来，对于降热尚未形成有效的措施。本课题组的前期研究结果表明，适当设计的粗糙单元能够明显降低高超声速边界层内部的摩阻和热流，但其物理机制有待进一步揭示，设计方法有待进一步明确。因此，本课题提出基于粗糙单元实现高超声速边界层降热减阻的流动控制理念，探索同时实现层流区的延迟转捩和湍流区的降热减阻的新型流动控制技术。为达到这一研究目标，需要综合稳定性分析理论，高精度数值模拟和风洞试验测量，对粗糙单元延迟边界层转捩和降热减阻的机理进行深入考察。同时考虑流动条件、粗糙单元的几何参数及安装位置等影响因素，形成适用于高超声速边界层、基于流动结构进行控制、能够同时兼顾层流区延迟转捩和湍流区降热减阻的新型流动控制技术，为我国未来高超声速飞行器的降热减阻设计提供技术支持。

众所周知，由于湍流摩阻和热流为层流的3-5倍，降热减阻对高超声速飞行器的整体性能至关重要。当前，高超声速飞行器的减阻技术主要从低速流动中推广过来，对于降热尚未形成有效的措施。本课题组的前期研究结果表明，适当设计的粗糙元能够明显降低高超声速边界层内部的摩阻和热流，但其物理机制有待进一步揭示，设计方法有待进一步明确。因此，本课题提出基于粗糙单元实现高超声速边界层降热减阻的流动控制理念，探索同时实现层流区的延迟转捩和湍流区的降热减阻的新型流动控制技术。为达到这一研究目标，需要综合稳定性分析理论，高精度数值模拟和风洞试验测量，对粗糙元延迟边界层转捩和降热减阻的机理进行深入考察。同时考虑流动条件、粗糙单元的几何参数及安装位置等影响因素，形成适用于高超声速边界层、基于流动结构进行控制、能够同时兼顾层流区延迟和湍流区降热减阻的新型流动控制技术，为我国未来高超声速飞行器的降热减阻设计提供技术支持。