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

基础设施和车辆上的冰和霜的积累每年给美国造成数十亿美元的经济损失。使用热和防冻化学品来除冰是昂贵的，对环境有害，机械除冰通常是不切实际的，可能会损坏下面的表面。这个GOALI项目将开发一种全新的除冰方法，利用冰可以自发通电的事实。实验测量和数值模拟的结合将表征冰和霜在各种条件下可以带电的程度。通过在冰面上放置带电的电极，由于产生的静电力，它可以被迫从下面的表面迅速分离。这种新的静电除冰技术将用于三种不同的冰：平面冰原、树突冰原和霜冰。该研究团队将与罗尔斯·罗伊斯公司合作，在飞机上应用静电除冰，以保护喷气发动机免受有害冰的摄入。研究人员还将为西弗吉尼亚州科学博物馆举办一个展览，将静电除冰的概念与云的电气化联系起来。该项目有两个主要目标：全面了解冰中的电荷分离，并利用这种效应实现静电除冰。众所周知，冰中电荷分离的主要机制是温差的存在，这导致某些（自然发生的）离子缺陷比其他离子缺陷优先迁移。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，缺乏可控的实验或数值验证，并且狭隘地关注云电气化的特定背景。相比之下，该项目将利用复杂的数值技术结合先进的实验表征。温度梯度、环境条件和冰/霜的几何结构会有很大的变化，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提高冰中电荷分离的程度和施加相反的电荷来快速分离冰并将其从表面移除来利用。这种新的除冰结构，称为静电除冰，是前所未有的。除了实现实用和新颖的除冰结构外，关于冰中电荷分离的见解将有助于更好地理解云的电气化。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。

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.