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用两个几何相似大小不同的前缘后掠角 70°三角翼模型在闭口风洞中进行正弦俯仰振荡实验 ,测量三角翼模型吸力面动态压力以及风洞洞壁上最佳测压点的非定常压力。实验表明 ,三角翼模型在正弦俯仰振荡时 ,其吸力面动态压力以及洞壁上最佳测压点的非定常压力与三角翼模型上的法向力一样呈现迟滞环现象。模型展宽比 (翼展 /洞宽 )增大 ,迟滞环幅度增大 ,动态压力绝对值增大。无论上仰或下俯 ,模型展宽比 (翼展 /洞宽 )增大 ,三角翼模型吸力面涡破碎位置离前缘较远。风洞顶壁上最佳测压点非定常压力迟滞环方向与风洞底壁上对应最佳测压点非定常压力迟滞方向相反。风洞洞壁上最佳测压点非定常压力变化频率与模型正弦俯仰振荡频率一致 ,各最佳测压点间呈现时间延迟现象。
Using two similar geometrically similar 70 ° delta wing models with leading edge sweep angle, a sinusoidal pitch oscillation test was carried out in a closed wind tunnel to measure the dynamic pressure on the suction surface of the delta wing model and the non-optimal pressure measurement point on the wind tunnel wall Constant pressure. The experimental results show that the dynamic pressure of the suction surface and the unsteady pressure of the optimum pressure measurement point on the wall of the delta wing show the same hysteresis loop as the normal force on the delta wing model during sinusoidal pitch oscillation. Model aspect ratio (span / hole width) increases, hysteresis loop amplitude increases, the absolute value of dynamic pressure increases. Regardless of uplift or down, the model aspect ratio (span / hole width) increases, the delta wing model suction surface vortex crushing position farther away from the leading edge. The best pressure-measuring point on the top of the wind tunnel Unsteady pressure The direction of the hysteresis loop is opposite to that of the best pressure-measuring point on the bottom wall of the wind tunnel non-steady-state pressure hysteresis. Wind tunnel wall pressure points of the best unsteady pressure changes with the model sine pitch oscillation frequency, the best pressure measurement point between the time delay phenomenon.