不同分布式螺旋桨转向组合下的机翼滑流效应研究

Study on wing slipstream effects of distributed propellers with different rotating directions

  • 摘要: 目前航空喷气式发动机仍为运输类飞行器的主要动力且仍在不断进步,但关于未来航空运输的分布式螺旋桨推进、分布式涵道推进等各类电推进概念研究早已开始,并将成为未来运输类航空飞行器的核心竞争力。文中首先采用等效盘方法对单独螺旋桨进行算例验证,计算得到的拉力、扭矩与试验结果吻合较好,且与非定常时间平均的滑流速度分布相近;然后,基于雷诺平均N-S方程,结合SA湍流模型,运用无厚度圆盘代替真实分布式螺旋桨,完成四种分布式螺旋桨旋转组合下的机翼滑流效应研究;最后,对单个螺旋桨正反转情况下的滑流效应进行研究,特别是单个螺旋桨滑流对机翼升阻力增量影响情况。分析结果表明:四种分布式螺旋桨转向组合下的滑流效应均引起机翼升阻力增大;机翼升力与其上下表面吸力峰数量关系密切,而分布式螺旋桨的转向组合直接决定了机翼吸力峰数量,特别是翼尖螺旋桨转向;相邻桨叶转向相反时,其转轴中间位置桨叶均处于上行或下行状态,使得转轴中间区域机翼前缘吸力相对转向同向状态有所加强或减弱;翼尖螺旋桨逆翼尖涡方向旋转具有增升减阻效果,反之则增阻减升。

     

    Abstract: Nowadays, developing aviation jet engines are the main driving force for transport vehicles. The study on electric propulsion concepts with distributed propellers and distributed duct fans for the transport vehicles has already begun, and the new propulsion is the core competence of future transport aviation aircraft. In this paper, the actuator disk method is used to verify individual propeller firstly, and the calculated thrust and torque agree well with the test results. Then, based on Reynolds averaged N-S equations and combined with the SA turbulence model, the wing slipstream effects on of distributed propellers with different rotating directions under the condition of low speed and high thrust at low altitude are analyzed by replacing the distributed propellers with actuator disk. Finally, the wing slipstream effects of single propeller with positive and negative rotating directions are studied, especially the effects on the lift and drag. The results show that the lift and drag of the aircraft with slipstream effects are both greater than those without slipstream effects for four types of distributed propeller rotating direction. The lift is closely related to the number of suction peaks on the upper and lower surfaces, and the types of distributed propeller rotating direction directly determine the number of wing suction peaks, especially the wing tip rotating direction. When adjacent blades rotate in the opposite directions, the blades in the middle position of the rotation shaft are both in the upward and downward states, leading to strengthened or weakened wing suction of the leading edge in the middle position compared with that in the same rotating direction. Moreover, as the wingtip propeller rotates in the direction opposite to the wingtip vortex rotating, the lift increases and the drag decreases.

     

/

返回文章
返回