EAGER/Collaborative Research: Revealing the Physical Mechanisms Underlying the Extraordinary Stability of Flying Insects

这个探索性研究的早期概念拨款（EAGER）研究了某些昆虫如何在飞行过程中忍受大的干扰，而不会失去控制。自由飞行的飞蛾的高速图像显示，这种昆虫在被冲动加速到每秒5000度的旋转速度后，只拍打几下翅膀就恢复了正常飞行。计算机模拟表明，这种快速恢复可能是由于飞蛾身体的突然运动所产生的类似弹簧的空气力。在此之前，人们并不认为这些力量对飞蛾的飞行很重要。本项目将使用数学分析和高保真计算机模拟来充分探索和解释这一惊人的结果。从这项工作中获得的知识将有助于保护未来的飞机；所观察到的行为超出了当前飞行控制技术的能力。初步分析表明，在观测到的从脉冲加速恢复到高音高速率的能力中，身体增加的质量效应起了核心作用。本研究将采用理论和计算相结合的方法来了解机体飞行动力学和非定常流之间的相互作用，其时间尺度明显快于机翼拍动周期。具体任务包括：(1)体添加质量效应的动力学分析和与现有昆虫飞行干扰响应数据的比较；（ii）对附加质量效应的高保真计算流体动力学模拟，以及（iii）对存在涡流的附加质量效应的分析。该研究将包括开发在未来无人驾驶飞行器上实施新理解的高速率恢复机制的方法。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This EArly-concept Grant for Exploratory Research (EAGER) investigates how certain insects may tolerate large disturbances during flight, without tumbling out of control. High-speed images of a free-flying hawkmoth showed the insect -- after being impulsively accelerated to a spin rate of 5,000 degrees per second -- returning to normal flight in only a few wing beats. Computer simulations suggest that this rapid recovery may be due to a spring-like force from the air displaced by the sudden motion of the moth’s body. These forces were not previously thought to be important in hawkmoth flight. This project will use mathematical analyses and high-fidelity computer simulations to fully explore and explain this surprising result. The knowledge gained from this work will help safeguard future aircraft; the observed behavior is beyond the capability of current flight control technology. Preliminary analysis suggests that the body-added mass effect plays a central role in the observed ability of the hawkmoth to recover from impulsive acceleration to high pitch rates. This study will apply a combination of theoretical and computational methods to understand the interplay between body flight dynamics and unsteady flow, at timescales significantly faster than the wing beat period. Specific tasks include (i) dynamic analysis of body added mass effects and comparison to existing insect flight disturbance response data; (ii) high-fidelity computational fluid dynamic simulations of added mass effects, and (iii) analysis of added mass effects in the presence of vortical flow. The study will include development of approaches to implement the newly understood high-rate recovery mechanisms on future unpiloted aerial vehicles.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.