飞行器绕流流场脉动压力环境预示方法探讨

Discussion on Prediction Methods of Fluctuating Pressure Environments of Flow Fields Surrounding the Aircraft

目的预示飞行器绕流流场的脉动压力环境。方法基于湍流理论,根据飞行器绕流流场脉动压力的产生机理、流动特征及其研究难度进行分析,从理论研究、风洞实验、数值模拟等研究手段探讨脉动压力环境的预示方法,并考虑工程问题中飞行器绕流的高马赫数、高雷诺数特征,对比不同研究方法的优劣。结果风洞实验是获取飞行器脉动压力环境的有力手段,针对典型外形的实验数据,结合理论推导分析,拟合获得了一系列半经验关系式。时均流场与半经验关系式相结合的方法能够快速评估获得飞行器表面的脉动压力环境,在工程中广泛应用。直接数值模拟方法能够精确刻画流场结构,准确预示脉动压力环境,应用前景光明。结论风洞实验、基于半经验公式和时均流场的预示方法以及直接数值模拟方法在飞行器脉动压力环境预示中能够发挥重要作用。

In order to predict fluctuating pressure environments of flow fields surrounding the aircraft,this paper,based on turbulence theory,analyzes the generative mechanism,flow characteristics and study difficulty of fluctuating pressure of the flow field around aircraft,discusses the prediction methods of fluctuating pressure environments by means of theoretical research,wind-tunnel test and numerical simulation,and compares the advantages and disadvantages of different research methods with the consideration of the characteristics of high Mach number and high Reynolds number.Finally,wind-tunnel test is a powerful method to obtain fluctuating pressure environments of aircraft.According to the experimental data of typical aerodynamic shapes,a series of semi-empirical correlations have been obtained by combining with theoretical derivation and analysis.The combination of time-averaged flow field and semi-empirical correlations can evaluate fluctuating pressure environments of the aircraft’s surface quickly,which is used widely in engineering.And direct numerical simulation can describe the flow field structure and predict fluctuating pressure environments accurately,so that it has a bright application prospect.In a word,wind-tunnel test,the prediction method based on semi-empirical correlations and time-average flow field,and direct numerical simulation can play an important role in predicting fluctuating pressure environments surrounding the aircraft.