• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文会议>ASME conference on smart materials, adaptive structures and intelligent systems >ALULA-INSPIRED LEADING EDGE DEVICE FOR LOW REYNOLDS NUMBER FLIGHT
【24h】

ALULA-INSPIRED LEADING EDGE DEVICE FOR LOW REYNOLDS NUMBER FLIGHT

机译：用于低雷诺数飞行的ALULA启发式前沿设备

获取原文
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Robust and predictable aerodynamic performance of unmanned aerial vehicles at the limits of their design envelope is critical for safety and mission adaptability. In order for a fixed wing aircraft to maintain the lift necessary for sustained flight at very low speeds and large angles of attack (AoA), the wing shape has to change. This is often achieved by using deployable aerodynamic surfaces, such as flaps or slats, from the wing leading or trailing edges. In nature, one such device is a feathered structure on birds' wings called the alula. The span of the alula is 5% to 20% of the wing and is attached to the first digit of the wing. The goal of the current study is to understand the aerodynamic effects of the alula on wing performance. A series of wind tunnel experiments are performed to quantify the effect of various alula deployment parameters on the aerodynamic per- formance of a cambered airfoil (S1223). A full wind tunnel span wing, with a single alula located at the wing mid-span is tested under uniform low-turbulence flow at three Reynolds numbers, Re = 85,000, 106,00 and 146,000. An experimental matrix is developed to find the range of effectiveness of an alula-type device. The alula relative angle of attack measured measured from the mean chord of the airfoil is varied to modulate tip-vortex strength, while the alula deflection is varied to modulate the distance of the tip vortex to the wing surface. Lift and drag forces were measured using a six axis force transducer. The lift and drag coefficients showed the greatest sensitivity to the the alula relative angle of attack, increasing the normalized lift coefficient by as much as 80%. Improvements in lift are strongly correlated to higher alula angle, with β = 0° - 5°, while reduction in the drag coefficient is observed with higher alula tip deflection ratios and lower β angles. Results show that, as the wing angle of attack and Reynolds number are increased, the overall lift co- efficient improvement is diminished while the reduction in drag coefficient is higher.
机译：在设计极限范围内，无人机的鲁棒和可预测的空气动力学性能对于安全性和任务适应性至关重要。为了使固定翼飞机能够以非常低的速度和较大的迎角（AoA）维持持续飞行所必需的升力，机翼的形状必须改变。这通常是通过从机翼前缘或后缘使用可展开的空气动力学表面（例如襟翼或板条）来实现的。在自然界中，一种这样的装置是鸟的翅膀上的羽毛状结构，称为alula。翼展的范围是机翼的5％到20％，并附着在机翼的第一个手指上。当前研究的目的是了解飞翼对机翼性能的空气动力学影响。进行了一系列风洞实验，以量化各种Alula部署参数对弧度翼型的空气动力学性能的影响（S1223）。在均匀的低湍流下，在三个雷诺数分别为Re = 85,000、106,00和146,000的低湍流下，对全风洞跨度机翼（位于机翼中跨处）进行了测试。开发了一个实验矩阵来发现alula型设备的有效性范围。从翼型的平均弦测得的测得的相对涡旋角改变以调节叶尖涡旋强度，而改变相对涡旋角以改变尖端旋涡到机翼表面的距离。使用六轴力传感器测量升力和阻力。升力和阻力系数显示出对alula相对攻角的最大敏感性，将归一化的升力系数提高了多达80％。 β= 0°-5°时，升力的提高与较高的alula角密切相关，而较高的alula尖端挠度比和较低的β角则可观察到阻力系数的减小。结果表明，随着机翼迎角和雷诺数的增加，升力系数的总体改善将减弱，而阻力系数的降低则更大。

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