摘要
分别从采用轴对称假设和考虑非对称性的角运动方程出发,通过对高超声速下(M=6)10°半锥角旋转钝锥双平面拍摄风洞自由飞试验结果进行气动参数辨识,对旋转钝锥高超声速自由飞行状态下气动导数的非对称性问题进行了分析。通过对比辨识曲线与观测值的重合性,证明轴对称旋转飞行器存在气动导数非对称的问题,其动导数和Magnus力矩导数均存在较明显的非对称性,动导数的非对称性尤其严重,而静导数的对称性则较好。进一步分析发现气动导数的非对称性对旋转飞行器的瞬态角运动、及总迎角的峰、谷值及相位均存在明显影响,采用轴对称假设而获得的瞬态角运动将存在一定误差。旋转飞行器气动导数非对称性的影响不可忽略。
Research on unsymmetrical aerodynamic derivatives of an axisymmetric spinning cone was conducted,the aerodynamic parameter identification results of wind tunnel free-flight tests of a spinning blunt cone at Mach 6 were analyzed using biplanar optical system,and two an-gular motion equations were adopted for symmetrical and unsymmetrical aerodynamic derivative coefficients respectively.Comparing the coincidence degree between fitting curves and raw data, it can be found that the fitting curves of equations with unsymmetrical aerodynamic derivatives is better agreed with raw data,than the curves with symmetry assumption.That proves the pres-ence of unsymmetrical aerodynamic derivatives for the axisymmetric spinning vehicle in hyperson-ic flow,similar to that in supersonic flow.Analysis shows dynamic derivative and Magnus mo-ment derivative are both unsymmetrical between the in-plane and out-plane components,only the static derivative is in good agreement with symmetry assumption.The unsymmetry of dynamic derivative is considerably severe.So the dynamic derivative in only one component cannot predict the dynamic stability exactly,the other component is also indispensable,espectcally the unsym-metrical dynamic derivative.Furthermore,the dynamic derivative predicted by symmetry as-sumption would be much higher than the true value for one component,and much lower for the other component.Further investigation shows unsymmetrical aerodynamic derivatives have obvious effect on transient angular motion of spinning vehicle,thus the angular motion behaviour cannot be mod-eled accurately with symmetrical stability derivative characteristic.The similar effect on peak-val-ley value and phase of total angle of attack curve are also discussed.Anyway,the effect of axi-symmetric spinning vehicle unsymmetrical aerodynamic derivative cannot be neglected.
出处
《空气动力学学报》
CSCD
北大核心
2015年第5期649-654,660,共7页
Acta Aerodynamica Sinica
基金
国家自然科学基金(11202200)
关键词
旋转钝锥
非对称气动导数
风洞自由飞试验
高超声速
spinning cone
unsymmetrical aerodynamic derivatives
wind tunnel free-flight test
hypersonic
