小迎角高超声速非旋转钝锥非线性运动分析

采用分段拟合技术对小迎角高超声速(马赫数Ma=6)非旋转钝锥双平面拍摄风洞自由飞试验结果进行了分析,获得了非旋转钝锥在小迎角高超声速下气动导数非线性的具体形式,分析了非旋转钝锥在小迎角下的非线性运动特点。研究发现在小迎角范围内钝锥的动导数系数均呈现明显的非线性,而静导数系数非线性较弱,可近似为线性。各组试验的静、动导数系数的非线性形式表明,除模型Ⅱ外的其余模型均为两方向振幅不同的极限圆锥运动,模型Ⅱ为极限平面运动。每组试验两个平面的静导数系数在小迎角范围内保持基本相等。而无论出现极限圆锥运动的四组试验还是出现极限平面运动的一组试验,模型在俯仰和偏航两个方向的动导数系数均存在较大差异。

Analysis of nonlinear motion for hypersonic non-spinning blunt cones at small angle of attack

With over-lapping sectional fitting technique, the data of wind-tunnel free-flight tests with biplanar optical system at Mach number 6 and small angle of attack, are analyzed. The concrete form of nonlinear aerodynamic derivatives of hypersonic non-spinning blunt cones at small angle of attack is acquired and the characteristic of nonlinear motion of non-spinning cones is studied. The obvious nonlinearity of dynamic stability derivative coefficient has been found at small angle of attack, while the nonlinearity of static stability derivative coefficient is so weak that it can be considered as almost linear. The nonlinear form of aerodynamic derivative coefficients indicate that all the test models appear limit coning motion with different amplitudes between the pitch and yaw direction, except that one model appears limit planar motion. The static stability derivative coefficients are nearly equal in pitch and yaw directions at small angle of attack for each test. All the models, appearing both limit coning motion and limit planar motion, present different dynamic stability derivative coefficients between pitch direction and yaw direction.