A Fundamental Study on Unsteady Heat Transfer and Dynamic Ice Accretion Processes Pertinent to UAV Icing Protection

无人驾驶飞行器（UAV），也被称为无人机，是航空界最引人注目的发展之一，具有新兴的民用和军事应用。与传统的大型有人驾驶飞机在高空巡航不同，轻型无人机专门设计用于在低空空域飞行，因此更容易受到结冰天气（如冻雨，雪和雨夹雪）的影响。目前的无人机防冰策略是将无人机保持在地面或修改其飞行路径，从而大大降低了无人机在寒冷气候下的操作能力。这对于救生搜索救援行动和军用无人机应用尤其令人不安，其中结冰条件将导致任务中止和关键战术能力的丧失。该项目旨在提高我们对无人机结冰物理学的理解，并开发新的防/除冰策略，以确保无人机在所有天气条件下的飞行安全。该项目还将包括重要的教育活动，包括多年的研究生/本科生研究计划，新的教学模块的开发，以及为本地K-12学生提供的外展计划，重点是促进女生和来自代表性不足的少数群体（URM）的学生的参与。该项目的目标是进行基础研究，以描述重要的微观物理过程（也就是说，非稳态传热、瞬态表面水回流和动态积冰过程）。表面性质的影响（例如，将系统地评估在无人机机翼和旋转螺旋桨上的动态积冰过程中的疏水性和导热性）。本文将进行一项探索性研究，以开发一种新的低功耗和有效的无人机飞行结冰缓解策略。还将进行全面的室外飞行试验活动，以在大气结冰天气下飞行实验性无人机（例如，雪、冻雨和雨夹雪），以填补理想化的实验室实验和真实的无人机飞行结冰过程之间的知识空白。拟议的研究将显着提高我们对无人机结冰物理的理解。它还将导致一种新的低功耗和有效的防/除冰策略，以确保无人机在所有天气条件下的飞行安全，这对救生搜索&救援行动和美国国防和国家安全关注的军用无人机应用非常关键。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的评估被认为值得支持。影响审查标准。

Unmanned-Aerial-Vehicles (UAVs), also known as Drones, is one of the most remarkable developments in the aviation community with emerging civilian and military applications. Unlike conventional, large-sized, manned aircraft cruising at high altitudes, light-weighted UAVs are designed specifically to fly in low-altitude airspace, thus, are much more vulnerable to the impacts of icing weather such as frozen rain, snow, and sleet. Current UAV icing avoidance strategy is either keeping UAVs on the ground or modifying their flight paths, thereby, greatly reducing the UAV operation capability in cold climate. This is particularly troubling for life-saving search & rescue operations and military UAV applications, in which icing conditions would lead to aborted missions and loss of crucial tactical capabilities. This project aims to improve our understanding about the underlying UAV icing physics and to develop novel anti-/de-icing strategies for assured UAV flight safety in all weather conditions. The project will also encompass significant educational activities, including a multi-year graduate/undergraduate research program, development of new teaching modules, and an outreach program for local K-12 students with a focus of promoting the participation of female students and those from under-represented minority (URM) groups.The goal of this project is to conduct a fundamental study to characterize the important micro-physical processes (i.e., unsteady heat transfer, transient surface water runback, and dynamic ice accretion process) pertinent to UAV inflight icing phenomena. The effects of the surface properties (e.g., hydrophobicity and thermal conductivity) on the dynamic ice accretion process over UAV wings and rotating propellers will be evaluated systematically. An explorative study will be performed to develop a new class of low-power and effective strategies for UAV inflight icing mitigation. A comprehensive outdoor flight test campaign will also be conducted to fly experimental UAVs in atmospheric icing weather (e.g., snow, frozen rain, and sleet) to fill the knowledge gaps between the idealized lab experiments and realistic UAV inflight icing process. The proposed research would significantly improve our understanding about the underlying UAV icing physics. It will also lead to a new class of low-power and effective anti-/de-icing strategies for assured UAV flight safety in all weather conditions, which are very critical to life-saving search & rescue operations and military UAV applications of America’s defense and national security concerns.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.