空天飞行器可调进气系统关键问题研究进展

Research progress on key issues of adjustable inlet system for aerospacevehicles

空天飞行器未来在军民诸多领域均能够扮演极其重要的角色,其关键技术之一便是能够在大气层内提供动力的吸气式组合循环发动机。进气道作为吸气式组合循环发动机的关键部件,迫切需要解决几何/气动大范围调节需求、宽域内流的精细化组织和预测需求以及发动机多模态间的平稳转换需求。为回应上述3大需求,可调进气系统需要在定几何/变几何调节技术、激波主导流动机理及控制技术、模态转换中流场动态演化特性这3个方面加深研究。就研究现状而言,转动是二元进气道的主要调节方式;平动是轴对称进气道的主要调节实现方式;变形调节对于二元和轴对称可调进气道均具有重要的补充和辅助价值。国内外研究人员对于激波/边界层干扰机理、进气道喘振机理、不起动/再起动迟滞机理等均建立了较为深刻的认识,在不起动/再起动边界的建模与预测方面也取得了相当大的进展,边界层放气依然是对激波主导流动中各种不利现象的有效控制措施。在模态转化方面,外并联组合进气道流道间的耦合干扰较弱,内并联组合进气道则表现出较为明显的流道间耦合干扰。未来,还应重点发展高效轻质的进气道调节技术,努力建立面向宽域可调进气道的快速设计体系,加强模态转换过程中进气道复杂内流机理研究,并积极与发动机控制学科交叉,突破智能化进气道调控技术,支撑我国空天飞行器的研制迈上新的台阶。

Aerospace vehicles are expected to play extremely important roles in military and civilian applications.One of the key technologies is the airbreathing combined-cycle engine that provides propulsion within the atmosphere.As a key component of the air-breathing combined-cycle engine,the air inlet urgently requires solutions to broad geometric/aerodynamic adjustment requirements,the intricate organization and prediction needs of wide-area internal flow,and the smooth transition demands between multiple engine modes.In response to these three major needs,the variable air inlet system necessitates further research in fixed geometric/variable geometric adjustment technology,shockdominated flow physics and flow control technology,and the dynamic evolution characteristics of the flow field during mode transition.Regarding the current state of research,rotation is the primary adjustment method for rectangular in-lets;translation is the principal adjustment implementation method for axisymmetric inlets;deformable modulation holds a significant complementary and auxiliary value for both rectangular and axis-symmetric adjustable inlets.Researchers,both domestically and internationally,have gained a deep understanding of shock wave/boundary layer in-teractions,inlet buzz mechanisms,and unstart/restart hysteresis mechanisms,and made considerable progress in the modelling and prediction of the unstart/restart boundaries.Boundary layer bleeding remains an effective control measure against various detrimental phenomena in shock-dominated flows.In terms of mode transition,external overunder inlets exhibit relatively weak inter-flowpath coupling interaction,whereas internal over-under inlets display more significant inter-flowpath coupling effects.In the future,emphasis should be placed on developing efficient and lightweight adjustment technology,establishing a rapid design system for wide-envelope adjustable inlets,strengthening research on complex internal flow mechanisms during mode transition,and actively intersecting with engine control disciplines to break through intelligent inlet control technology,thereby supporting the development of China's aerospace vehicles to a newlevel.