复合式飞行器前飞状态气动干扰特性分析

发布时间：2018-01-14 05:28

本文关键词：复合式飞行器前飞状态气动干扰特性分析　出处：《吉林大学》2016年硕士论文　论文类型：学位论文

【摘要】：共轴反桨直升机在前飞时既要保持升力,同时又要提供前行所需要的推力。则上下旋翼的间距势必要增加,旋翼的转动平面也会有所前倾导致一侧间距大而一侧间距小,间距比较小的一侧容易产生因挥舞严重而导致的碰撞问题,同时也会增加动力系统的功率损耗。因此本文提出加装两个尾部推进涵道配合前置短翼以平衡机身的复合式气动布局方案。提出采用两个尾部推进涵道来提供前飞推力,为保持机身的整体平衡在机身前部加装短翼,同时又可提供辅助升力,这样一来主旋翼只需要产生升力,避免了碰撞危险的发生达减小了发动机的功耗。首先对该无人机的整体气动布局进行描述,绘制主要结构三维SolidWorks模型,对具体参数进行计算。然后对尾部推进涵道以及前置短翼进行理论分析,为后文分析推进涵道的气动特性奠定理论基础,分析机翼产生升力的原理。在对尾部推进涵道的理论基础之上结合CFD仿真分析方法对涵道风扇的推力特性进行分析,分析得出不同变量以及不同螺旋桨环境对其气动特性的影响。运用CFD仿真方法分析机翼对尾部推进涵道在前飞时的气动干扰特性,对机翼流场特性分析得出机翼翼尖部分在前飞时会产生漩涡。通过改变不同涵道安装位置得出,翼尖的漩涡进入涵道风扇的位置也会有所不同。针对这种现象分别分析不同涵道安装位置时推进涵道的气动特性,并与不受短翼影响时的气动特性做分析对比。结果表明这种双尾部推进涵道配合前置短翼的气动布局不但会为无人机提供前飞的推力,同时涵道风扇的气动特性不会受到翼尖漩涡的影响,证明了此布局的合理性。
[Abstract]:The coaxial reverse propeller helicopter must maintain the lift and provide the thrust required for the forward flight, and the distance between the upper and lower rotor is bound to increase. The rotating plane of the rotor will also have a forward tilt, which will lead to a large distance between one side and a small distance. The side with small spacing will easily cause a collision problem caused by serious flapping. At the same time, the power loss of the power system will be increased. Therefore, this paper proposes a compound aerodynamic layout with two rear propulsion ducts to balance the fuselage and two rear propulsion ducts to provide the front. Flying thrust. In order to maintain the overall balance of the fuselage, a short wing is installed at the front of the fuselage, while at the same time providing auxiliary lift, so that the main rotor only needs to produce lift. The collision hazard is avoided and the power consumption of the engine is reduced. Firstly, the overall aerodynamic layout of the UAV is described, and the 3D SolidWorks model of the main structure is drawn. The specific parameters are calculated. Then the rear propulsion ducts and the front wing are theoretically analyzed, which lays a theoretical foundation for the later analysis of the aerodynamic characteristics of the propulsion ducts. Based on the theory of rear propulsion ducts, the thrust characteristics of ducted fans are analyzed by CFD simulation. The effects of different variables and different propeller environments on its aerodynamic characteristics are obtained. The aerodynamic interference characteristics of the wing to the rear propulsion ducts are analyzed by using CFD simulation method. By analyzing the flow field characteristics of the wing, it is found that the wing tip will produce swirl in the forward flight, which is obtained by changing the installation position of the different ducts. According to this phenomenon, the aerodynamic characteristics of propulsion ducts with different culvert installation positions are analyzed respectively. Compared with the aerodynamic characteristics of the UAV without the influence of the short wing, the results show that the double tail propulsion ducts and the front short wing will not only provide the forward thrust for the UAV. At the same time, the aerodynamic characteristics of the culvert fan are not affected by the wingtip vortex, which proves the rationality of the layout.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：V211

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