摘要
吸气式高速飞行器内外流高度耦合,激波-边界层干扰严重,壁面温度会影响边界层内的流动,进而影响气动特性。因此,准确评估风洞试验中的壁温效应,提高气动特性的预测精度,对飞行器设计至关重要。通过常规超高速风洞试验,结合数值模拟分析,开展了内流壁温对气动特性的影响规律及作用机理研究。结果表明:在常规超高速风洞几十秒的运行时间内,随着运行时间增加,飞行器内流道壁面温度不断升高,俯仰力矩以及内流道壁面压力均会出现显著变化,其中俯仰力矩的增加量需要2°舵偏角来平衡;此外,数值模拟分析进一步指出,飞行器俯仰力矩的变化主要原因是内流道壁面温度升高、边界层增厚、近壁低速区挤压中心的高速区,使得内流道等效面积减小、气流压缩,相应的马赫数减小、压力升高,并引起内流道激波波系前移,从而改变了内流道压力分布,最终导致俯仰力矩发生变化。
For air-breathing high-speed vehicles,inner and outer flows are highly coupled and there are strong interactions between shockwaves and boundary layers.Boundary layers are sensitive to the variation of the wall temperature,so do the aerodynamic characteristics.Consequently,how to predict the wall-temperature effect exactly and improve the prediction accuracy of aerodynamic characteristics are important for the design of high-speed vehicles.In this article,the effect of the inner flow wall temperature on aerodynamic characteristics is investigated through wind-tunnel measurements and numerical simulations.Results show that in conventional hypersonic wind tunnels,the inner wall temperature of the high-speed vehicle model increases continuously with the wind-tunnel running time,yielding significant variations of the pitching moment and wall pressure.The maximum increment of the pitching moment requires an increase of the rudder angle by 2°.In addition,numerical simulation results indicate that the thickness of boundary layer in the internal flow increases with the rise of wall temperature.Moreover,the equivalent area of high-speed flow channel decreases so that the flow is compressed.The change of velocity profiles in boundary layers results in the forward moving of shockwaves in the internal flow channel,which causes the change of pitching moment of high-speed vehicles.
作者
武利龙
罗金玲
李超
肖志祥
操小龙
WU Lilong;LUO Jinling;LI Chao;XIAO Zhixiang;CAO Xiaolong(Beijing Electro-mechanical Engineering Institute,Beijing 100074,China;Beijing Aerospace Technology Institute,Beijing 100074,China;School of Aerospace Engineering,Tsinghua University,Beijing 100084,China)
出处
《空气动力学学报》
CSCD
北大核心
2022年第1期84-91,共8页
Acta Aerodynamica Sinica
关键词
吸气式高速飞行器
壁温效应
内流
激波
边界层
air-breathing high-speed vehicle
wall-temperature effect
inner flow
shock wave
boundary layer
