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Particle motion in stratified turbulent flows

分层湍流中的粒子运动

基本信息

批准号：
414195707
负责人：
Dr.-Ing. Tian Ma
金额：
--
依托单位：
Institut für Fluiddynamik
依托单位国家：
德国
项目类别：
Research Fellowships
财政年份：
2018
资助国家：
德国
起止时间：
2017-12-31 至 2020-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/414195707?language=en
关键词：
Particle motion stratified turbulent flows

项目摘要

The interaction between inertial particles and turbulence is of fundamental importance in many environmental and engineering flows. Most previous studies on the topic have considered the simplified case of inertial particle motion in homogeneous isotropic turbulence. However, little is known about the behavior of inertial particles in stratified turbulence, despite its importance in natural and technologically relevant flows such as cloud formation, motion of plankton, air pollution meteorology, etc.The present proposal is intended for a research stay at Duke University, Durham, North Carolina in the group of Prof. Bragg who combines various novel theoretical methods with corresponding numerical simulations to investigate inertial particle motion in turbulence. The goal of the stay is to explore in detail the motion of inertial particles in stratified turbulence. More specifically, the research proposal incorporates three major objectives to be investigated. First, a systematic study using Direct Numerical Simulation (DNS) is intended to explore the effects of fluid stratification on the transport and mixing of inertial particles in turbulence. Second, turbulence generation due to particle clustering (i.e. production of fluid kinetic energy results from momentum coupling with particles) will be quantified by the various terms of the Reynolds-stress budget evaluated by DNS data. The generated results can then advance the turbulence model development considering cluster-induced turbulence. The third objective is to use the dispersion theory and DNS data to develop a simplified turbulent dispersion model to predict particle motion in stratified turbulence that can be used for engineering large-scale calculations. In addition to the technical goals, this research stay will bridge the established research groups dealing with DNS and modeling and build up a scientific network between Europe and USA.

惯性颗粒与湍流之间的相互作用在许多环境和工程流动中具有根本的重要性。以往对这一问题的研究大多考虑了均匀各向同性湍流中惯性粒子运动的简化情况。然而，人们对惯性粒子在分层湍流中的行为知之甚少，尽管它在自然和技术相关的流动中很重要，如云的形成，浮游生物的运动，空气污染气象学等。本建议打算在达勒姆的杜克大学进行研究停留，北卡罗来纳州在布拉格教授的小组中，他将各种新颖的理论方法与相应的数值模拟相结合，研究惯性粒子湍流中的运动停留的目的是详细探索分层湍流中惯性粒子的运动。更具体地说，研究提案包括三个主要的研究目标。首先，采用直接数值模拟（DNS）的系统研究，旨在探讨流体分层的惯性颗粒在湍流中的传输和混合的影响。第二，湍流生成由于颗粒聚集（即生产的流体动能的结果与颗粒的动量耦合）将被量化的各种条款的DNS数据评估的应力预算。所产生的结果，然后可以推进湍流模型的发展，考虑集群诱导的湍流。第三个目标是使用色散理论和DNS数据开发一个简化的湍流色散模型来预测分层湍流中的颗粒运动，该模型可用于工程大规模计算。除了技术目标外，此次研究停留还将在处理DNS和建模的现有研究小组之间建立桥梁，并在欧洲和美国之间建立科学网络。