低雷达散射截面机身的气动特性研究

本文通过对三个具有低雷达散射截面(RCS)隐身特性的“板块”多边形截面机身模型及通常的圆截面机身模型进行的低速气动特性的研究,包括迎角直到50°的低速风洞测力试验、水洞流谱试验及初步的工程估算结果与实验结果的比较,发现多边形截面机身不但具有良好的隐身特性,而且其气动特性也并不比圆截面机身差,其升力特性及最大升阻比大大优于圆截面机身;同时,在大迎角零侧滑条件下,能产生稳定的侧力,其值大于圆截面机身的侧力,发生迎角小于圆截面机身的发生迎角。多边形截面机身的气动力计算方法目前尚不成熟。本文建议在小展弦比机翼的计算方法基础上,按相应截面的外形特征给出修正方法,其计算结果接近实验结果。

An Approach to Aerodynamic Charateristics of Low Radar Cross-Section Fuselages

This paper presents that the polygonal section fuselages are better than the circular section fuselage not only in stealthy characteristics (low RCS), but also in aerodynamic characteristics, specially in lift force and maximun lift-drag ratio, by investigating the low speed aerodynamic characteristics for three "panel" polygonal section fuselage models with low RCS and one regular circular section fuselage model, including the low speed tunnel testing of measuring forces, water tunnel field visualization and the comparison between the results of the engineering evaluation and experiments at the angle of attack up to 50 degrees. Moreover, they can produce steady sideforces which are larger than those of the circular section fuselage at the high angles of attack and zero sideslip, and the produced angle of attack is lower than that of circular one. The aerodynamic calculation method of polygonal section fuselage has not been perfected upto now. In this paper a correction evaluation method is proposed that is given according to the contour characteristics of the corresponding section on the basis of the calculation method of low aspect ratio wing and the calculation results are in good agreement with those of the experiments.