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进行液态金属实验是不可行的，因此将使用高保真度模拟。该研究计划将对制造业产生长期影响，这是一个国家关注的研究领域，例如在涉及电流熔化矿石的铝生产中，以及磁场。该研究计划的目标是在均匀磁场中导电流体湍流研究方面取得根本性进展，在低磁雷诺数区域。高保真度的数值模拟（即，湍流的直接数值模拟（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。磁流体湍流的性质还没有得到充分的理解--只有很少的实验数据。被动标量场的模拟提出了从不同的初始条件的混合和松弛的时间尺度上的见解。建议的DNS将提供结果来模拟考虑焦耳耗散效应的雷诺应力张量，并关闭低阶建模的湍流方程。此外，还提议为最近的一项暑期实习方案倡议开展一项培训活动，该方案专门针对残疾本科生，将通过与美国科学促进协会密切合作，从全国申请者库中挑选。来自亚特兰大地区参加暑期项目的选定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.