Numerical and Experimental Study of the Electrohydrodynamic Atomization of Highly Conducting Liquids, Including Dissipation Effects

主要研究者：Gamero，Manuel提案编号：1604163拟议研究的目标是推进对电喷雾过程中所涉及的流体动力学的理论理解。在该过程中，通常用于制造良好控制的纳米液滴或纳米纤维，高导电流体通过锥形喷射孔。最近的实验数据表明，能量耗散在高导电流体的电喷雾中很重要，特别是当形成纳米级液滴时。制造业和纳米技术都被确定为国家需要的领域。本项目的目的是获得一个基本的了解，电喷雾的高导电液体在锥射流模式，与新列入的热效应。高导电性液体的锥形射流的重要性在于其产生纳米液滴的均匀喷雾的独特能力，这在制造、航天器推进和超高速撞击研究中具有极大的兴趣。虽然在锥形射流模式下的电喷雾已被分析的基础上的漏电介质模型，最近的实验工作表明，能量耗散是显着的高电导率，纳米政权，有必要补充机械漏电介质模型与能量守恒方程来解决温度场。考虑到温度的实际变化很重要，因为粘度、电导率和表面张力等关键参数对温度的依赖性很强。本项目将制定和数值求解保留热效应的锥形射流过渡区的二维轴对称电流体动力学模型，并测量锥形射流特性（包括I（Q）定律和能量耗散），以验证模型。实验测量，特别是能量耗散的测量，必须在真空环境中使用飞行时间和减速电位分析仪的组合来完成。该项目包括两个影响更广泛的组成部分：基础研究，同时促进教学、培训和学习;促进代表性不足的群体的参与。拟议的研究将通过以下方式注入初中和高中学生：a）与当地K-12学区合作，包括开发活动，如实验室开放日和与拟议研究相关的物理学和技术应用的偶尔讲座;和B）高中生暑期实习，从事NSF项目。

PI: Gamero, ManuelProposal Number: 1604163The goal of the proposed research is to advance theoretical understanding of the fluid dynamics involved in the process known as electrospraying. In this process, often utilized for the manufacturing of well-controlled nanodrops or nanofibers, highly conducting fluids pass through a cone-jet orifice. The proposed research is motivated by recent experimental data showing that energy dissipation is important in electrosprays of highly conducting fluids, especially when nanoscale drops are formed. Manufacturing and nanotechnology have been both identified as areas of National need. The objective of this project is to obtain a fundamental understanding of the electrospraying of highly conducting liquids in the cone-jet mode, with the novel inclusion of thermal effects. The importance of cone-jets of highly conductivity liquids resides in its unique ability for generating uniform sprays of nanodroplets, which are of great interest in manufacturing, spacecraft propulsion and hypervelocity impact research. Although electrospraying in the cone-jet mode has been analyzed on the bases of the leaky dielectric model, recent experimental work has demonstrated that energy dissipation is significant in the highly conductivity, nanometric regime, making it necessary to supplement the mechanical leaky dielectric model with an equation of conservation of energy to resolve the temperature field. Accounting for the actual variation of temperature is important because of the strong temperature dependence of key parameters like viscosity, electrical conductivity, and surface tension. This project will formulate and numerically solve a 2-D, axisymmetric electrohydrodynamic model of the transition region of cone-jets that retains thermal effects, and measure cone-jet characteristics (including the I(Q) law, and the dissipation of energy) with the goal of validating the model. The experimental measurements, in particular the measurement of energy dissipation, must be done in a vacuum environment using a combination of time of flight and retarding potential analyzers. The project includes two broader impact components: fundamental research while promoting teaching, training and learning; and promoting the participation of underrepresented groups. The proposed research will be infused into middle and high school students through: a) a collaboration with the local K-12 school district including the development of activities such as laboratory open-houses and occasional lectures on physics and technological applications associated with the proposed research; and b) summer internships for high school students to work on the NSF project.