Onset of Turbulence in Dusty Plasma Liquids

本课题通过对尘埃粒子在等离子体环境中的运动进行数值模拟，研究在由电子、离子和尘埃粒子构成的等离子体的带电介质中引导湍流发生的基本物理机制。 了解带电介质中从层流到湍流的转变是非常重要的科学挑战之一，因为它会影响核聚变、化学品在大气中的分散、大气风暴的形成和飞机稳定性等复杂过程。例如，飞行湍流是常见的，但这种现象的起源可能受到各种因素的影响，包括气流、压力或温度梯度以及自感应电，包括尘土飞扬的大气中的闪电。 在等离子体条件下，尘埃粒子变得带电，并可以形成尘埃等离子体液体，其中可以观察到各种波和不稳定性。尘埃等离子体的动力学行为受尘埃与尘埃之间的相互作用以及尘埃与等离子体之间的相互作用的影响，这两种相互作用都可能导致尘埃的异常扩散。在这个项目中，研究小组将调查异常扩散和全球不稳定性（如湍流）之间的联系。研究小组将开发一个内部分析代码，采用光谱理论和分数阶微积分的新数学技术来模拟具有非局部相互作用的无序介质中的异常粒子扩散。对于给定的扩散行为，分析代码将基于其能谱的演化来确定系统的相应的时间演化动力学状态。为了验证这一新技术，从光谱分析的预测将比较从分子动力学模拟的结果，以及实验采用尘埃等离子体液体表现出turbulentbehavior.This奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

This project will investigate the fundamental physical mechanisms guiding onset of turbulence in charged media, a plasma composed of electrons, ions, and dust particles, by numerically modeling the motion of dust particles in the plasma environment. Understanding the transition from laminar to turbulent flow in charged media is one of the very important scientific challenges as it affects complex processes such as nuclear fusion, dispersion of chemicals in the atmosphere, formation of atmospheric storms, and aircraft stability. For example, flight turbulence is common, yet the origin of such phenomenon can be affected by a variety of factors, including wind flows, pressure or temperature gradients, and self-induced electricity, including lightning, in dusty atmospheres. In plasma conditions, the dust particles become charged and can form dusty plasma liquids, where various waves and instabilities can be observed. This makes dusty plasmas an ideal model system for the study of the laminar-to-turbulent transition.The dynamics of dusty plasmas is guided by the dust-dust interaction and the dust interaction with the plasma, both of which can lead to anomalous dust diffusion. In this project, the research team will investigate the connection between anomalous diffusion and the onset of a global instability, such as turbulence. The research team will develop an in-house analysis code, employing novel mathematical techniques from spectral theory and fractional calculus to model anomalous particle diffusion in disordered media with non-local interactions. For a given diffusion behavior, the analysis code will determine the corresponding time-evolved dynamical state of the system based on the evolution of its energy spectrum. To verify this novel technique, the predictions from the spectral analysis will be compared against the results from molecular dynamics simulations as well as experiments employing dusty plasma liquids exhibiting turbulent behavior.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.