UNS: Strained Turbulence and Mixing in Flows of a conducting fluid in a magnetic field

1510749（Yeung）本提案的目的是研究在涉及液态金属的制造过程中发生的湍流中磁力的影响。由于在这些物理系统中使用液态金属进行实验是不可行的，因此将利用高保真度模拟。这项拟议中的研究预计将对制造业以及磁场产生长期影响。制造业是美国感兴趣的一个研究领域，例如在铝的生产中，涉及到熔化矿石的电流。提出的研究目标是在低磁雷诺数条件下，在均匀磁场中导电流体的湍流研究中取得基本进展。湍流的高保真数值模拟（即直接数值模拟，DNS）将用于研究在这种物理情况下重要的磁流体动力学（MHD）现象以及电磁感应的洛伦兹力对流动发展和混合的影响。MHD湍流的性质还没有得到充分的了解——可用的实验数据很少。提出了被动标量场的模拟，以提供不同初始条件下混合和松弛的时间尺度的见解。所提出的DNS将提供计算焦耳耗散效应的雷诺应力张量的结果，并关闭低阶建模的湍流方程。此外，在与美国科学促进会（American Association for the Advancement of Science）密切合作的情况下，在最近的暑期实习项目中提出了一项专门针对残疾本科生的培训活动，这些学生将从全国申请者中挑选出来。从亚特兰大地区选出的参加暑期课程的高中教师将被鼓励将科学元素纳入高中物理课程。

1510749(Yeung)The goal of this proposal is to investigate effects of magnetic forces in turbulent flows that occur in manufacturing processes where liquid metals are involved.High fidelity simulations will be utilized, since experiments in these physical systems with liquid metals are not feasible. The proposed research is expected to have a longer term impact on manufacturing, a research area of National interest, for example in the production of aluminum that involves electrical currents that melt the ore), as well as magnetic fields.The objectives of the proposed research are to pursue fundamental advances in the study of turbulent flow of an electrically conducting fluid in a uniform magnetic field, in the low-magnetic-Reynolds number regime. Numerical simulations of high fidelity (i.e., direct numerical simulations, DNS) of turbulent flows will be utilized to study the magnetohydrodynamic (MHD) phenomena that are important in this physical situation and the effects of the Lorentz force of electromagnetic induction on flow development and on mixing. The nature of MHD turbulence is not sufficiently understood - very little experimental data are available. Simulations of passive scalar fields are proposed to provide insights on time scales of mixing and relaxation from different initial conditions. The proposed DNS would provide results to model the Reynolds stress tensor accounting for the Joule dissipation effect and to close the turbulence equations for lower-order modeling. In addition, a training activity is proposed to recent initiatives in a summer internship program specifically targeted towards undergraduate students with disabilities, to be selected from a national pool of applicants through working closely with the American Association for the Advancement of Science. Selected high school teachers from the Atlanta area participating in a summer program will be encouraged to incorporate elements of the science into high-school physics curricula.