CAREER: Liquid-drop impacts on granular surfaces and the universality in granular impact cratering

职业：液滴对颗粒表面的撞击以及颗粒撞击坑的普遍性

• 批准号: 1452180
• 负责人: Xiang Cheng
• 金额: $ 46.87万
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-02-15 至 2021-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1452180&HistoricalAwards=false
• 关键词: CAREER; Liquid; drop; impacts; granular

Non-Technical AbstractGranular impact cratering by liquid drops is likely familiar to all of us who have watched raindrops splashing in a backyard or on a beach. Such a ubiquitous phenomenon is directly relevant to many important natural, agricultural and industrial processes such as soil erosion, drip irrigation, dispersion of micro-organisms in soil, and spray-coating of particles and powders. It is even more surprising that granular impact cratering by liquid drops and asteroid impact cratering on planetary bodies show quantitatively similar features in terms of the energy scaling and the shape of impact craters. The present project investigates the fast dynamics of impinging liquid drops and impacted granular particles during impact events, which are then used to develop a quantitative model for describing the morphology of raindrop imprints in granular media. The project also aims to reveal universal features of granular impact cratering and search the link between different granular cratering processes including solid-sphere impact cratering, liquid-drop impact cratering, asteroid impact cratering and explosion cratering. To probe the fast impact dynamics, students working on the project are trained in the state-of-the-art high-speed and radiological imaging techniques. The project can provide practical guides to various activities in environmental protection and industry involving liquid-drop impacts on granular surfaces.Technical AbstractDirectly related to two long-standing problems in soft matter research, i.e., drop impact on solid/liquid surfaces and granular impact cratering by solid spheres, liquid drop impact on granular surfaces is notoriously complicated. The objective of the project is to investigate the dynamics of liquid-drop impact on granular surfaces and explore universal features of granular impact cratering across widely different energy scales. Combining high-speed photography with advanced radiological imaging techniques, the study aims to uncover the detailed dynamics of liquid-drop impact in granular media and provide a quantitative model for predicting of the outcome of liquid-drop impact events. The experimental techniques and physical insights developed in the research are considerably useful for solving difficult problems faced in the study of drop impact dynamics and granular impact cratering in much broader contexts. Moreover, the study helps to illustrate universal features in granular impact cratering and may open up a new way to probe high-energy granular impact cratering associated with asteroid strikes. The study can also potentially benefit soil science research on soil erosion, astrophysical research on asteroid strikes and geological research on primordial rain activities.

非技术摘要液滴的颗粒状撞击坑可能对我们所有人都很熟悉，我们都看到过雨滴在后院或海滩上飞溅。这种普遍存在的现象与许多重要的自然、农业和工业过程直接相关，如土壤侵蚀、滴灌、微生物在土壤中的扩散以及颗粒和粉末的喷涂。更令人惊讶的是，液滴形成的颗粒状撞击坑和小行星撞击行星体形成的撞击坑在能量比例和撞击坑形状方面表现出数量上相似的特征。本项目研究的快速动力学的撞击液滴和撞击颗粒在撞击事件，然后被用来开发一个定量模型来描述雨滴印迹在颗粒介质中的形态。 该项目还旨在揭示颗粒撞击成坑的普遍特征，并探索不同颗粒撞击成坑过程之间的联系，包括固体球体撞击成坑、液滴撞击成坑、小行星撞击成坑和爆炸成坑。为了探测快速撞击动力学，参与该项目的学生接受了最先进的高速和放射成像技术的培训。该项目可为环境保护和工业中涉及液滴冲击颗粒表面的各种活动提供实用指导。技术摘要直接涉及软物质研究中两个长期存在的问题，即，液滴对固体/液体表面的冲击和固体球体的颗粒冲击成坑，众所周知，液滴对颗粒表面的冲击是复杂的。该项目的目标是研究液滴撞击颗粒表面的动力学，并探索不同能量尺度下颗粒撞击成坑的普遍特征。结合高速摄影与先进的放射成像技术，该研究旨在揭示颗粒介质中液滴撞击的详细动力学，并为预测液滴撞击事件的结果提供定量模型。在研究中开发的实验技术和物理的见解是相当有用的解决困难的问题所面临的研究中的下降冲击动力学和颗粒的冲击成坑在更广泛的背景下。此外，这项研究有助于说明颗粒撞击坑的普遍特征，并可能开辟一种新的方式来探测与小行星撞击有关的高能颗粒撞击坑。这项研究还可能有益于土壤侵蚀方面的土壤科学研究、小行星撞击方面的天体物理学研究和原始降雨活动方面的地质学研究。