GOALI: Fundamental Studies on High Impact Pressure, Supersonic Water Droplets for Material Deformation and Removal

GOALI：高冲击压力、超音速水滴材料变形和去除的基础研究

• 批准号: 1462993
• 负责人: Brad Kinsey
• 金额: $ 30万
• 依托单位: University of New Hampshire
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-03-01 至 2022-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1462993&HistoricalAwards=false
• 关键词: GOALI; Fundamental; Studies; Impact; Pressure

Ultra high pressure, high velocity continuous columns of water jets are used in a number of applications, e.g., as a carrier for grit in water jet cutting of metals. Under ideal conditions, the water pressure of the jet is equal to the pressure head generated by the pump. However, past research has shown that the breakup of the stream into droplets produces impact pressures that significantly exceed the water-hammer pressure. This Grant Opportunity for Academic Liaison with Industry (GOALI) award supports fundamental research into droplet formation and droplet-surface interaction phenomena. Results from this research can help achieve their applications from peening to coating removal to machining in a more economical and environmentally friendly manner. This will benefit society at large by creating environmentally friendly processes with significantly less water usage and contaminated materials compared to competing technologies. Objectives of this research are to (1) assess the effect of various process parameters, i.e., co-flow gas velocity, partial chamber pressure, high frequency instability triggering, and reduced Weber number on droplet formation; (2) determine the droplet characteristics, i.e., droplet velocity, diameter, and spacing, that are required to create the desired droplet-surface interaction results (e.g., residual stresses, surface roughness, or material removal rate); (3) characterize the material behavior and triaxial stress failure mechanisms at high deformation rates; and (4) implement a multi-jet system that can process large surface areas and study additional process parameters, i.e., jet spacing and individual jet pressure. The tools that will be used in this research are (i) an experimental set-up which includes measurement of key process parameters, i.e., visualized droplet characteristics listed above, droplet force, and temperature; and (ii) a suite of predictive finite element models that capture the droplet-surface interaction results. The methodologies used will be both experimental (to allow process parameters to be controlled, measured, and explored) and numerical with validated models (to allow further investigation of the design space compared to simply a trial-and-error experimental approach). The knowledge gained from this research will also benefit the study of other physical phenomena, e.g., cavitation erosion. The academic, industrial, and national laboratory partners have significant expertise in fluid dynamics and solid mechanics modeling, experimental methods, material characterization, machine development, and manufacturing, pertinent to assuring the success of this research.

超高压，高速度连续的水喷头柱用于许多应用中，例如，在金属切割金属中的砂砾中用作砂砾。在理想条件下，射流的水压等于泵产生的压力头。 然而，过去的研究表明，流到液滴的破裂产生的冲击压力大大超过了水锤压力。这项与行业联络的赠款机会（Goali奖）支持对液滴形成和液滴表面相互作用现象的基本研究。这项研究的结果可以帮助以更经济和环保的方式实现从剥离到涂层到加工的应用。与竞争技术相比，这将通过创建用水量和受污染材料的环境友好的过程来使社会受益。 这项研究的目的是（1）评估各种过程参数的影响，即共流气体速度，部分腔室压力，高频不稳定性触发以及减少Weber数量对液滴形成的影响； （2）确定液滴特性，即液滴速度，直径和间距，这些液滴速度，直径和间距是创建所需的液滴表面相互作用结果所需的（例如，残余应力，表面粗糙度或材料去除速率）； （3）以高变形率以材料行为和三轴应力失败机制来表征； （4）实施一个可以处理大型表面积并研究其他过程参数的多喷射系统，即喷射间距和单个喷气压力。在这项研究中将使用的工具是（i）实验设置，其中包括测量关键过程参数，即上述可视化的液滴特性，液滴力和温度； （ii）捕获液滴表面相互作用的一组预测有限元模型。 所使用的方法既是实验性的（允许对过程参数进行控制，测量和探索），也将使用经过验证的模型进行数值（与简单的试验实验方法相比，允许对设计空间进行进一步研究）。从这项研究中获得的知识也将受益于其他物理现象的研究，例如空化侵蚀。学术，工业和国家实验室伙伴在流体动力学和固体力学建模，实验方法，材料表征，机器开发和制造业方面具有重要的专业知识，这与确保这项研究的成功有关。