| 项目编号: | 1604272
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| 项目名称: | Exploiting Vapor Pressure Gradients to Suppress In-Plane Frost Growth |
| 作者: | Jonathan Boreyko
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| 承担单位: | Virginia Polytechnic Institute and State University
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| 批准年: | 2016
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| 开始日期: | 2016-08-15
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| 结束日期: | 2019-07-31
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| 资助金额: | 328298
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| 资助来源: | US-NSF
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| 项目类别: | Standard Grant
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| 国家: | US
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| 语种: | 英语
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| 特色学科分类: | Engineering - Chemical, Bioengineering, Environmental, and Transport Systems
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| 英文关键词: | ice
; in-plane
; inter-droplet
; dry zone
; frost
; surface
; growth
; out-of-plane inter-droplet ice
; fundamental understanding
; electrical intervention
; wegener-bergeron-findeisen process
; evolving-boundary computational model
; wind turbine
; inter-droplet frost growth
; mechanical integrity
; marine structure
; ice formation
; vapor gradient
; inter-droplet evaporation
; mixed-phase
; dew point
; miniscule structure
; vapor transfer
; frost growth
; electric heating
; in-plane frost growth
; in-plane growth
; water vapor
; source-sink interaction
; localized pressure gradient
; experimental insight
; vapor-liquid-ice multiphase system
; fundamental insight
|
| 英文摘要: | 1604272
Boreyko, Jonathan B.
Ice formation can heavily compromise the mechanical integrity and energy efficiency of systems such as aircraft, marine structures, power grids, wind turbines, and HVAC systems. The economic cost of ice formation amounts to billions of dollars every year. Active methods of removing ice include spraying chemicals or using electric heating, but such techniques are environmentally and energetically costly. Surfaces that could, by themselves, suppress the growth of ice for many hours or even days would therefore be highly advantageous, but to date, no such surface exists. This proposal seeks to develop smart surfaces that suppress the growth of ice without any mechanical or electrical intervention, leaving the majority of the surface dry even under chilled and humid conditions. The proposed surface will have miniscule structures that will guide the deposition of water in such a way as to reduce ice formation. System optimization will be obtained by modeling the thermodynamics and fluid dynamics of vapor transfer in vapor-liquid-ice multiphase systems, which could also shed fundamental insight on the behavior of mixed-phase clouds.
The objective of this proposal is to gain a fundamental understanding of the localized pressure gradients and resulting source-sink interactions between ice, water, and water vapor and to exploit this knowledge to passively suppress the in-plane growth of frost. Using a combination of experimental, theoretical, and computational techniques, the following research tasks are proposed: (1) Characterizing Inter-Droplet Frost Growth: In-plane and out-of-plane inter-droplet ice bridging between a frozen droplet and supercooled liquid droplet will be characterized using a custom-built humidity chamber and hydrophobic surfaces bonded to Peltier stages. The resulting data will be correlated with an evolving-boundary computational model. (2) Creating a Dry Zone around Ice: When a water droplet is frozen before surrounding condensate has a chance to grow appreciably, a stable dry zone forms between the ice droplet and the condensation. An isolated droplet will be frozen just above the dew point and then the humidity will be raised to observe and model the resulting dry zone. (3) Suppression of In-Plane Frost Growth: With the knowledge gained from the previous two tasks, a controlled array of microscopic stripes of ice will be formed on a chemically and/or physically patterned surface, such that the dry zone about each stripe of ice will overlap to keep the vast majority of the surface dry from condensate and frost. A fuller understanding of inter-droplet evaporation and ice bridging in mixed-phase water systems will clarify the thermodynamics and fluid dynamics of frost growth on surfaces and give experimental insight to the Wegener-Bergeron-Findeisen process of glaciation in mixed-phase clouds. Furthermore, the proposed research will map out the critical phase space where the vapor gradients result in ice bridging versus dry zones. |
| 资源类型: | 项目
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/91446
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| Appears in Collections: | 全球变化的国际研究计划
科学计划与规划
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| Recommended Citation: | |
Jonathan Boreyko. Exploiting Vapor Pressure Gradients to Suppress In-Plane Frost Growth. 2016-01-01.
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