Collaborative Research: bubble impacting a curved surface: a sustainable way to sanitize produce

合作研究：气泡撞击曲面：农产品消毒的可持续方法

• 批准号: 1920013
• 负责人: Lei Pan
• 金额: $ 16万
• 依托单位: Michigan Technological University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-15 至 2023-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1920013&HistoricalAwards=false
• 关键词: Collaborative; Research; bubble; impacting; curved

Cleaning practices using microbubbles have been proven to be a sustainable and environmently benign sanitation method in a wide range of industrial applications. When a stream of bubbles impact and slide on a surface, contaminants on the surface can be removed due to the strong force generated by the bubbles. Bubble-cleaning of agricultural produce like fruits and vegetables has not been studied extensively. Potentially, this method could be used to minimize cases of food poisoning affecting millions of people every year, since bubble streams could be used to remove and inactivate pathogenic microorganisms from produce surfaces. Understanding the bubble-surface interaction is challenging due to the fact that the process transpires over multiple length scales, in which bubble deformation and trajectory occur on the order of a millimeter while the liquid film between the bubble and solid involves only a few hundreds of nanometers. This research project could lead to a novel technology for an environmentally benign sanitization process for raw fruits and vegetables. The method could even be applied to other technological processes such as semiconductor manufacturing. The research project serves as a training ground for graduate and undergraduate students to perform cutting edge research. The research team will make an instructional video on how to make a bubble-stream fruit cleaner and share it via social media and web-based outlets at Cornell University. Farmers could use the video to learn how to put together their own bubble cleaners.The goal of this collaborative research project is to investigate both macro- and microscopic dynamics of a bubble impacting and sliding along a surface. This research will elucidate how bubbles remove particulate dirt or biological micro-organisms from a surface. There are limited studies in bubbly flows on tilted or curved surfaces, even though bubbles are used to clean various surfaces in many industrial processes. The research team will use high-speed photography, particle image velocimetry, pressure distribution measurements, and an interferometry microscopy technique to characterize shear and normal stresses, as well as thickness profiles of an asymmetric thin liquid film while bubbles impact on a surface. The research project involves three tasks:1) characterizing the macroscopic dynamics of a bubble on a surface as a function of the inclination angle and the curvature; 2) experimentally measuring and computationally modeling the shear stress and interfacial deformation of a bubble near the surface; and 3) testing the particle-scavenging and retaining performance of bacteria using agricultural products. The outcomes of this research will lead to an understanding of the underlying fluid mechanics in bubble sanitization technology.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.

使用微泡的清洁实践已被证明是一种可持续的和无害的卫生方法，在广泛的工业应用。当气泡流冲击并在表面上滑动时，由于气泡产生的强大力，表面上的污染物可以被去除。水果和蔬菜等农产品的气泡清洁尚未得到广泛研究。 这种方法有可能用于减少每年影响数百万人的食物中毒病例，因为气泡流可用于去除和消除产品表面的病原微生物。 理解气泡表面相互作用是具有挑战性的，因为该过程在多个长度尺度上发生，其中气泡变形和轨迹发生在毫米量级上，而气泡和固体之间的液体膜仅涉及几百纳米。这项研究项目可能会导致一种新的技术，用于对生水果和蔬菜进行环境友好的消毒过程。 该方法甚至可以应用于其他工艺过程，如半导体制造。该研究项目作为研究生和本科生进行尖端研究的培训基地。 该研究小组将制作一个关于如何制作气泡流水果清洁剂的教学视频，并通过康奈尔大学的社交媒体和网络渠道分享。 农民可以通过视频学习如何组装自己的气泡清洁器。这个合作研究项目的目标是研究气泡撞击和沿沿着滑动的宏观和微观动力学。 这项研究将阐明气泡如何从表面去除颗粒污垢或生物微生物。尽管气泡在许多工业过程中被用于清洁各种表面，但对倾斜或弯曲表面上的气泡流的研究有限。该研究小组将使用高速摄影，粒子图像测速，压力分布测量和干涉显微镜技术来表征剪切应力和法向应力，以及气泡冲击表面时非对称薄液膜的厚度分布。 该研究项目包括三个任务：1）表征表面上气泡的宏观动力学，作为倾角和曲率的函数; 2）实验测量和计算模拟表面附近气泡的剪切应力和界面变形; 3）使用农产品测试细菌的颗粒清除和保留性能。这项研究的成果将有助于理解气泡消毒技术中的基本流体力学。该奖项反映了NSF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。