SGER: Hydrophobic Surface Effects on Sheet Cavitation

SGER：疏水表面对片层空化的影响

• 批准号: 0649572
• 负责人: Roger Arndt
• 金额: --
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-09-15 至 2008-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0649572&HistoricalAwards=false
• 关键词: SGER; Hydrophobic; Surface; Effects; Sheet

PROPOSAL NO.: CTS-0649572PRINCIPAL INVESTIGATORS: R. ARNDTINSTITUTION: UNIVERSITY OF MINNESOTASGER: Hydrophobic Surface Effects on Sheet CavitationThis is an exploratory research project aimed at capitalizing on recent research experience with unsteady partially cavitating flows. This work has identified the significant and unexpected effect of surface properties and water quality on the dynamics of these flows. Previously it was thought that surface properties and water quality only affected cavitation inception physics. At the same time there has been significant interest in the use of hydrophobic surfaces for drag reduction. Hybrid drag reduction drag reduction schemes involving a combination of microbubble injection coupled with the use of hydrophobic surfaces have also been proposed. The PIs will explore the possibility of using hydrophobic surfaces to control or minimize unwanted vibration and unstable operation in the partially cavitating regime. Before embarking on a significant research program that would involve the development of structured hydrophobic surfaces a limited exploratory effort will identify the potential for further development of this concept. Three surfaces will be evaluated, such as anodized aluminum (hydrophilic), Teflon (hydrophobic), and highly polished stainless steel (hydrophobic). Contact angle will be measured and based on the range of contact angle that is feasible, the PIs will predict the change in cavity length and estimate the change in lift dynamics on the basis of their previous experiments and with the help of their numerical model. They will then design and build three hydrofoils of identical cross section. The first will have a hydrophilic surface; the second hydrophobic and the third will have a hydrophobic surface for one half of the span and a hydrophilic surface for the other half of the span. Comparative measurements of unsteady lift will be made. High-speed video will be analyzed to determine fully wetted time. This research has important technological broader impacts. Operation into a regime of partial cavitation has been considered for hydrofoils and is becoming common in a wide range of turbomachinery applications. This opens up a wide range of new considerations including the possibility of control of these flows to eliminate or minimize unwanted vibration and unstable operation. The results of this will research will indicate whether the use of hydrophobic surfaces for control of cavitation induced vibration and unsteadiness is feasible.

提案编号： CTS-0649572主要制造商：R. ARNDT机构： 明尼苏达大学：这是一个探索性的研究项目，旨在利用最近的研究经验，与非定常部分空化流。这项工作已经确定了显着的和意想不到的影响，表面特性和水质对这些流动的动力学。以前人们认为表面性质和水质只影响空化起始物理学。与此同时，人们对使用疏水表面来减阻产生了极大的兴趣。混合减阻减阻方案，涉及微泡注射结合使用疏水表面的组合也被提出。PI将探索使用疏水表面来控制或最大限度地减少不必要的振动和不稳定的操作在部分空化制度的可能性。在开始一项涉及结构化疏水表面开发的重要研究计划之前，将进行有限的探索性工作，以确定进一步开发这一概念的潜力。 将对三种表面进行评价，例如阳极氧化铝（亲水性）、Teflon（疏水性）和高度抛光的不锈钢（疏水性）。将测量接触角，并根据可行的接触角范围，PI将预测空腔长度的变化，并根据其先前的实验并借助其数值模型估计升力动力学的变化。然后，他们将设计和建造三个相同横截面的水翼。第一个将具有亲水性表面;第二个疏水性表面和第三个将具有一半跨度的疏水性表面和另一半跨度的亲水性表面。将进行非定常升力的比较测量。将分析高速视频以确定完全润湿时间。 这项研究具有重要的技术广泛影响。 对于水翼，已经考虑了进入部分空化状态的操作，并且在广泛的气动应用中变得越来越普遍。这开辟了广泛的新的考虑因素，包括控制这些流量的可能性，以消除或最大限度地减少不必要的振动和不稳定的操作。本研究结果将显示使用疏水性表面控制空蚀诱发振动和不稳定性是否可行。