CAREER: Multiscale experimental framework on dynamics of deformable particles in turbulent dispersed multiphase flow

职业：湍流分散多相流中可变形粒子动力学的多尺度实验框架

• 批准号: 1653389
• 负责人: Rui Ni
• 金额: $ 50万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-03-01 至 2019-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1653389&HistoricalAwards=false
• 关键词: CAREER; Multiscale; experimental; framework; dynamics

From rain droplets in clouds to gas bubbles in bioreactors and nuclear reactors, multiphase flows occurring in nature and industrial applications are often turbulent, spanning a wide range of length and time scales and posing significant challenges to numerical and experimental methods. Significant progress has been made in characterizing the turbulent multiphase flow dispersed with spherical particles; much less is known, however, about another large category with dispersed phase consisting of deformable liquid drops or gas bubbles. Those particles can freely deform, tumble, break up and coalesce in turbulent flow, adding new degrees of freedom to an already complex problem. The key questions arise as to what are the statistics of unique dynamics of these deformable particles and how to characterize their complex couplings with the carrier phase. In order to address those questions and gain insights in the full physical picture of the dynamics of deformable particles, the project involves a multiscale experimental framework on several different length scales from interface dynamics to large-scale statistics. In order to obtain couplings of two phases, both the carrier phase and the dispersed phases will be tracked in the Lagrangian framework simultaneously. This enables us to measure, not only the velocity of both phases, but also those high-order derivatives, including acceleration and velocity gradient tensor, that are more important to the momentum couplings between two phases.

从云中的雨滴到生物反应器和核反应堆中的气泡，自然界中发生的多相流通常是湍流的，跨越了较宽的长度和时间尺度，并对数值和实验方法构成了重大挑战。在表征湍流流动以球形颗粒分散的湍流流动方面取得了重大进展。然而，众所周知，关于另一个大型类别，其分散相由可变形的液滴或气泡组成。这些颗粒可以在湍流中自由变形，翻滚，分解和聚结，从而为已经复杂的问题增加了新的自由度。关于这些可变形粒子的独特动力学的统计数据是什么，以及如何表征其复杂的耦合与载体相的统计数据。为了解决这些问题并获得可变形粒子动力学的完整物理图，该项目涉及从界面动力学到大规模统计数据的几个不同长度尺度上的多尺度实验框架。为了获得两个阶段的耦合，将同时在拉格朗日框架中跟踪载体相和分散阶段。这使我们不仅可以测量这两个阶段的速度，还可以测量那些高阶衍生物，包括加速度和速度梯度张量，这对于两个阶段之间的动量耦合更为重要。