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

Virginia Polytechnic Institute And State University, Blacksburg VA

Investigators

Abstract

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.