GOALI: Exploiting Charge Separation in Ice for Electrostatic De-Icing

在美国，基础设施和车辆上的冰霜堆积每年造成数十亿美元的经济损失。使用加热和防冻剂来除冰的成本很高，而且对环境有害，机械除冰往往是不切实际的，可能会损害下垫面。这个Goali项目将开发一种全新的除冰方法，利用冰可以自发带电的事实。实验测量和数值模拟相结合，将表征冰和霜在不同条件下可能带电的程度。通过将带电电极放置在冰上，可以迫使冰在产生的静电力的作用下迅速从下面的表面分离。这项新的静电除冰技术将在三种不同类型的冰上进行测试：平面冰盖、树枝状霜层和雾状冰。该研究小组将与劳斯莱斯合作，将静电除冰应用于飞机，以保护喷气式发动机免受有害冰块的摄入。研究人员还将为西弗吉尼亚州科学博物馆制作一个展览，将静电除冰的概念与云的带电联系起来。该项目的主要目标有两个：全面了解冰中的电荷分离，并利用这种效应实现静电除冰。人们已经知道，冰中电荷分离的主要机制是存在温差，这导致某些(自然发生的)离子缺陷优先于其他离子缺陷的迁移。然而，现有的冰中电荷分离模型仅适用于稳态，依赖于几个未经检验的假设，缺乏受控的实验或数值验证，并且狭隘地关注云带电的特定背景。相比之下，该项目将利用复杂的数值技术，并结合先进的实验表征。冰/霜的温度梯度、环境条件和几何结构将发生很大变化，以确定它们对电荷分离程度的影响。其次，这些发现将通过最大限度地扩大冰中电荷分离的程度并施加相反的电荷来快速分离并从冰表面移除来利用。这种被称为静电除冰的新除冰结构是史无前例的。除了实现实用和新颖的除冰结构外，在冰中电荷分离方面获得的见解将有助于更好地理解云的电气化。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The accumulation of ice and frost on infrastructure and vehicles results in billions of dollars in economic losses annually in the United States. The use of heat and antifreeze chemicals to remove ice is costly and harmful to the environment, and mechanical de-icing is often impractical and can damage underlying surfaces. This GOALI project will develop a completely novel approach to de-icing that exploits the fact that ice can become spontaneously electrified. A combination of experimental measurements and numerical simulations will characterize the extent to which ice and frost can become electrified under various conditions. By placing charged electrodes over the ice, it can be forced to rapidly detach from an underlying surface by virtue of the resulting electrostatic force. This new technique of electrostatic de-icing will be examined for three different kinds of ice: planar ice sheets, dendritic frost sheets, and rime ice. The research team will collaborate with Rolls-Royce in applying electrostatic de-icing to aircraft to protect jet engines from harmful ice ingestion. The researchers will also create an exhibit for the Science Museum of Western Virginia that connects the concept of electrostatic de-icing to the electrification of clouds.There are two primary objectives to the project: gaining a comprehensive understanding of charge separation in ice and exploiting the effect to enable electrostatic de-icing. It is already known that the primary mechanism for charge separation in ice is the presence of a temperature differential, which causes the preferential migration of certain (naturally occurring) ionic defects over others. However, existing models of charge separation in ice apply only at steady-state, rely on several untested assumptions, lack controlled experimental or numerical validation, and are narrowly focused on the specific context of the electrification of clouds. In contrast, the project will utilize sophisticated numerical techniques in conjunction with advanced experimental characterization. The temperature gradient, environmental conditions, and geometric structure of the ice/frost will be widely varied to determine their effect on the extent of charge separation. Second, these findings will be exploited by maximizing the extent of charge separation in ice and applying an opposing charge to rapidly detach and remove the ice from its surface. This new de-icing construct, termed electrostatic de-icing, is unprecedented. In addition to enabling a practical and novel de-icing construct, the insights gained regarding charge separation in ice will lead to a better understanding of the electrification of clouds.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.