• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文会议>International specialists meeting on unmanned rotorcraft 2009 >Experiments on the Optimization of MAV-Scale Cycloidal Rotor Characteristics Towards Improving Their Aerodynamic Performance
【24h】

Experiments on the Optimization of MAV-Scale Cycloidal Rotor Characteristics Towards Improving Their Aerodynamic Performance

机译：优化MAV比例摆线转子特性以改善其空气动力学性能的实验

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Studies of a MAV- scale cycloidal rotor (cyclocopter) were performed using performance and flow field measurements. Detailed parametric studies were conducted to determine the effects of rotational speed, the amplitude of the blade pitch angle, and the number of blades on cycloidal rotor performance. It was found that a 5-bladed cyclocopter system operating with 40° pitch produced the best power loading (thrust per unit power), with a figure of merit (based on the definition given in the paper) of 0.4. Thrust measurements suggested the presence of a sidewise force along with the vertical lift, similar to those found on rotating circular cylinders. This was confirmed using particle image velocimetry (PIV) measurements, which showed evidence of a wake skewness. The magnitudes of the measured vertical and sidewise forces were confirmed from the flow field measurements using a momentum balance technique. The thrust produced by the cyclocopter was found to increase until a geometric pitch of 40° was reached without showing any signs of blade stall. This behavior was explained using the PIV measurements, which showed the presence of high induced velocities in the rotor wake, which reduced angles of attack and delayed the occurrence of stall. Blade lift and drag were estimated from the flow field measurements, and were found to correlate well with the balance measurements. The PIV measurements clearly showed the rotational nature of the flow inside the cycloidal rotor, which is a significant source of energy loss, as well as the fact that the lower half of the rotor operates in the wake of the upper half. The induced power loss manifested as a large induced power factor in the modified momentum theory when compared to measurements.
机译：使用性能和流场测量对MAV规模的摆线旋翼（cyclocopter）进行了研究。进行了详细的参数研究，以确定转速，叶片桨距角的幅度以及叶片数量对摆线转子性能的影响。发现以40°俯仰运行的5叶片式旋翼直升机系统产生的最佳功率负载（每单位功率推力）为佳，品质因数（基于本文给出的定义）为0.4。推力测量表明，与垂直升力同时存在侧向力，类似于在旋转圆柱体上发现的力。使用粒子图像测速（PIV）测量已证实了这一点，该测量显示了尾流偏斜的证据。使用动量平衡技术从流场测量中确定了测得的垂直力和侧向力的大小。发现旋翼飞机产生的推力一直增加，直到达到40°的几何螺距，而没有出现桨叶失速的迹象。使用PIV测量可以解释此行为，该测量表明转子尾流中存在较高的感应速度，从而减小了迎角并延迟了失速的发生。叶片升力和阻力由流场测量值估算，并与平衡测量值很好地相关。 PIV测量清楚地显示了摆线转子内部流动的旋转特性，这是能量损失的重要来源，并且转子的下半部分在上半部分之后运转。与测量值相比，修正动量理论中的感应功率损耗表现为较大的感应功率因数。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号