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“2-lead”多直升机升力系统的气动干扰和性能变化
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作者 丁志伟 段登燕 +2 位作者 赵刚 宣金婷 李建波 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2023年第4期401-419,共19页
参与协同吊挂的直升机属于近距离编队飞行,旋翼尾流之间存在严重的气动干扰,从而带来复杂的气动力学耦合问题。因此在研究性能优化、先进编队控制之前,有必要研究协同吊挂系统的气动干扰及其带来的性能变化。本文以4架纵列式直升机组成... 参与协同吊挂的直升机属于近距离编队飞行,旋翼尾流之间存在严重的气动干扰,从而带来复杂的气动力学耦合问题。因此在研究性能优化、先进编队控制之前,有必要研究协同吊挂系统的气动干扰及其带来的性能变化。本文以4架纵列式直升机组成的“2-lead”队形的协同吊挂系统为研究对象,采用黏性涡粒子/面元法研究直升机协同吊挂系统稳定飞行状态下的性能和流场。其中,系统的稳定飞行状态通过分层配平法得到,涡/面法通过风洞试验数据验证。在此基础上,研究了不同飞行速度及不同直升机相对位置下的系统气动干扰和性能变化。计算结果表明:前飞时,研究对象中前后布置的直升机间存在严重的气动干扰。其中,前进比为0.1时,队列中后方纵列式直升机的前旋翼存在20%的推力损失和15%的功耗增加。当队列中直升机间的纵向距离大于3.5倍旋翼直径D、侧向距离大于0.75倍旋翼直径D,或垂向距离大于0.5倍旋翼直径D时,气动干扰均会大大降低。 展开更多
关键词 多升力 性能变化 气动干扰 涡方法 编队
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MULTI-BODY AEROELASTIC STABILITY ANALYSIS OF TILTROTOR AIRCRAFT IN HELICOPTER MODE 被引量:4
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作者 董凌华 杨卫东 夏品奇 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2006年第3期161-167,共7页
The muhi-body analysis of the aeroelastic stability of the tiltrotor aircraft is presented. Muhi-body dynamic differential equations are combined with the equations of the unsteady dynamic inflow model to establish th... The muhi-body analysis of the aeroelastic stability of the tiltrotor aircraft is presented. Muhi-body dynamic differential equations are combined with the equations of the unsteady dynamic inflow model to establish the complete unsteadily aeroelastic coupling analytical model of the tiltrotor. The stability of the tiltrotor in the helicopter mode is analyzed aiming at a semi span soft-inplane tihrotor model with an elastic wing. Parametric effects of the lag stiffness of blades and the flight speed are analyzed. Numerical simulations demonstrate that the multibody analytical model can analyze the aeroelastic stability of the tiltrotor aircraft in the helicopter mode. 展开更多
关键词 TILTROTOR HELICOPTER aeroelastic stability multi body dynamics dynamic inflow
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Capillary Rise between Parallel Perforated Plates in Microgravity 被引量:1
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作者 Diana Gaulke Michael E. Dreyer 《Journal of Physical Science and Application》 2014年第5期277-290,共14页
This paper presents the setup and performance of a drop tower experiment which investigates the behavior of liquid during self-driven capillary transport between two parallel perforated plates under microgravity. With... This paper presents the setup and performance of a drop tower experiment which investigates the behavior of liquid during self-driven capillary transport between two parallel perforated plates under microgravity. With the onset ofmicrogravity the liquid rises between the two parallel plates as a result of capillary pressure. Eight different sets of plates are tested in this study and the free surface height and the volume of transported liquid is subsequently analyzed. The plate sets differ in geometric properties of their perforations, distance, and width. In each set the perforations of both plates are identical and have a diameter of a few millimeters. The capillary rise velocity is influenced by the perforation diameter and the area porosity of the plates. As could be expected, the capillary transport capability increases with decreasing plate porosity. 展开更多
关键词 WETTING MICROGRAVITY CAPILLARY liquid rise WICKING pinning.
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