在排球扣球时,佯扣短平快,突然向前冲跳,“飞”到二传手前扣半高球。前飞的助跑路线与网夹角很小(有时可顺网助跑),击球时利用向左转体和收胸动作带动手臂挥动击球。 单脚起跳进行前飞扣球时,助跑的最后一步跨出左腿,步幅不宜过大,左脚蹬地的同时,右腿和双臂配合向前上方摆动,使身体向前上方冲跳。击球时,上体向左转动带动手臂挥动击球。击球后,双脚同时落地,以缓冲下落力量。
The results show that it is stable in the given forward flight. But the instability arises with the decrease of the bending and torsion stiffness of the shaft.
对某新型直升机的气动/机械稳定性进行了分析,结果发现对于给定的前飞状态是稳定的,但是随着传动轴弯曲和扭转刚度的降低出现不稳定现象。
参考来源 - 直升机旋翼/机身耦合系统气动/机械稳定性分析新方法 A NEW AEROMECHANICAL STABILITY ANALYSIS METHODOLOGY FOR COUPLED ROTOR/FUSELAGE SYSTEM OF HELICOPTERS·2,447,543篇论文数据,部分数据来源于NoteExpress
然后依据通用结构模型,利用飞行实测数据,得到悬停和前飞状态下的辨识模型。
According to the generic structural model, specific parameterized models in hover and forward flight are obtained by using the flight test data.
应用自由尾迹方法和旋翼配平模型,建立了一个悬停和前飞状态旋翼在导弹发射线上的诱导速度计算模型。
Based on the rotor free-wake model and the rotor trim model, an analytical method is developed for the prediction of helicopter rotor induced velocities on missile trajectory.
分析了直升机从悬停到小速度前飞时,定常垂直气流的非均匀分布对直升机平衡操纵以及对系统摆振后退型模态阻尼的影响。
The influences of nonuniform vertical flow on helicopter trim controls and regressive lag modal damping levels were analyzed in hovering and forward flight.
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