摘要
高超声速飞行器边界层容易经历层流/湍流转捩,层流流动和湍流流动在摩擦阻力、热交换、噪声和掺混等方面有巨大差别,转捩问题已成为制约高超声速技术突破的基础科学问题之一,是当前国际学术研究的热点与难点。本文详细分析了国内外高超声速边界层转捩研究现状,并将其归为三类:已知主要原因的现象与规律、已知部分原因的现象与规律、未知或矛盾的现象。其中已知主要原因的现象与规律包括壁温、马赫数和噪声影响;已知部分原因的现象与规律主要有头部钝度、熵层和攻角影响;未知或矛盾的现象主要有单位雷诺数影响、转捩区长度、转捩区摩阻和热流分布等。同时介绍了高超声速边界层转捩影响因素研究、转捩机理研究、转捩预测方法及模型研究、促进/推迟转捩的控制方法研究、以及一些公开的飞行试验等方面的进展。最后指出,在今后的高超声速边界层转捩研究中,建议把单个影响因素独立出来研究,尽量避免多因素相互干扰;高超声速边界层失稳研究需要特别关注横流失稳、熵层和模态相互作用;转捩预测需考虑三维边界层和来流扰动的影响;转捩控制研究应重点关注高效、低阻、低热的控制方法;转捩飞行试验十分重要,飞行试验和静音风洞发挥的作用会越来越明显。过去60多年的研究经验表明在未来的研究中应该注重多种手段相结合。
Hypersonic vehicles are likely to undergo laminar/turbulent boundary layer transition （BLT）. Laminar boundary layers and turbulent boundary layers show essential differences in skin friction, heat transfer, mixing, and noise. Hypersonic BLT is one of basic scientific problems, which restrict the development of advanced hypersonic technology. Nowdays, hypersonic BLT is a hot and difficult topic. Worldwide studies on hypersonic BLT are briefly summarized in this paper. The phenomena and regularities of hypersonic BLT are classified into three categories： what we know the main reasons, what we know parts of the reasons, and what we don＇t know or are inconsistency. Wall temperature effects, Mach number effects and wind tunnel noise effects are which we know the main reasons. Nose bluntness effects, angle-of-attack effects and entropy layer interference are which we only know parts of the reasons. Unit Reynolds number effects, length of transitional zones, surface friction and heat distributions in transitional zones are which we know little. Factors affecting hypersonic BLT, physical mechanisms of hypersonic BLT, methods and models of predicting hypersonic BLT, and and control methods of delaying/accelerating hypersonic BLT, are reviewed, together with unclassified hypersonic flight tests. In order to avoid interactions of different factors, it is suggested to detach individual factors from composite transition clauses and study these individual factors separately. In future study on hypersonic boundary layer instability, special efforts shall be focused on crossflow instability, entropy layer, and mode interactions. Future prediction methods and models need to account for three-dimensional flows and free-stream disturbances. Future control methods shall be high effective, and low additional drag and surface heating. Flight test is very important for the study of hypersonic BLT. Flight test and quiet wind tunnel are becoming more and more useful and fruitful. The past more than 60 years of studies on hypersonic BLT indicate the importance of the combination of different research methods, such as numerical simulations, wind tunnel experiments, flight tests, and stability analysis.
出处
《空气动力学学报》
CSCD
北大核心
2017年第3期311-337,共27页
Acta Aerodynamica Sinica
基金
国家重点研发计划项目(2016YFA0401200)
关键词
高超声速
边界层转捩
飞行试验
转捩预测
转捩控制
hypersonic
boundary layer transition
flight tests
transition prediction
transition control
