舰载机多体动力学建模与弹射起飞模拟

Multi-body Dynamics Modeling and Catapult-launching Simulation for Carrier-based Aircraft

考虑航母扰动以航母为参考系,建立了考虑机体弹性以及支柱弹性的舰载机弹射起飞多体动力学模型,将舰载机动力学方程推广到非惯性参考系下;通过增加自由停机和张紧停机过程,构建了弹射起飞全过程的数值模拟能力,并通过算例对建模可靠性进行了验证。算例结果准确模拟了牵制杆拉断后前起落架垂向的不稳定振荡现象、弹射力卸载后前起落架的快速突伸现象,以及起落架离舰效应等物理过程。算例结果表明:借助于起落架的突伸,飞机离舰前的升降舵偏角产生的抬头力矩能有效增加离舰的俯仰角和俯仰速度,提高弹射起飞性能;离舰后升降舵偏转控制律在提高飞机迎角建立速度的同时,还能控制最大飞行迎角,有利于离舰飞行安全;飞机离舰时航母舰艏的垂直速度、俯仰速度以及抛射角对飞机的离舰飞行性能有影响,航母运动会危及舰载机弹射起飞安全,且以纵摇和横摇运动的影响最为显著。

Regarding the flexibility of airframe and landing-gear strut, and taking the carrier as reference frame, the multi-body dynamics model of carrier-based airframe was established. For the first time, the dynamics equations of carrier-based aircraft were extended to non-inertial reference frame. By increasing the simulation procedure of free parking and tension parking, it had the full-process simulation capacity for catapult launch. The validity of the model was verified by a simulation example. The study on the effects of elevator angle and deck motion indicated that： by the aid of the gear fast extension, the nose-up pitching moment caused by elevator angle before flying off can increase pitch angle and pitch rate greatly at the flying-off time; besides speeding up the construction of angle of attack （AOA） , the control law for after flying-off elevator angle also control the maximum AOA during climbing, which is conductive to the safety of catapult launch; through the bow vertical velocity, rate of pitch and projecting angle of carrier, the deck motion have significant influence on the after flying-off flight performance. Deck motion endangers the safety of catapult launch of carrier-based aircraft; among the deck motions, the roll motion and pitch motion are more serious.