Direct Numerical Simulation of Fully Resolved Vaporizing Droplets in a Turbulent Flow

该奖项促进了科学研究使用大型新的计算资源命名为蓝色沃茨计划部署在伊利诺伊大学在2012年。它提供差旅费，以支持主要调查员、蓝色沃茨项目小组和供应商技术小组之间的技术协调。拟议的数值研究的目的是提高液滴蒸发和混合过程的湍流的理解。数值研究采用直接数值模拟（DNS）检查之间的双向相互作用的自由移动的蒸发液滴和各向同性湍流。液滴将在3D空间和时间中完全解析，即不被视为点粒子，并且湍流运动的所有尺度都被解析到最小的相关长度和时间尺度（柯尔莫哥洛夫尺度）。重点将放在蒸发液滴和周围的湍流气体之间的质量，动量和能量的双向交换。在未来的研究中，在考虑湍流剪切流之前，首先将湍流假设为各向同性。所提出的研究结果可能会影响能量的有效利用。这种影响源于这样一个事实，即蒸发率是燃料液滴燃烧的主要控制机制，液体燃料是所有运输方式的最重要能源，并将在可预见的未来保持这种状态。 了解湍流中蒸发和混合过程的物理细节是了解化学反应过程和最终控制/优化能量转换过程的必要前提。PI在研究领域和研究与教学相结合方面取得了成就，包括对本科生和科学领域代表性不足的学生的宣传。

This award facilitates scientific research using the large new computational resource named Blue Waters scheduled to be deployed at the University of Illinois in 2012. It provides travel funds to support technical coordination between the principal investigators, the Blue Waters project team and vendor technical team.The objective of the proposed numerical study is to enhance the understanding of liquid droplet vaporization and mixing processes in a turbulent flow. The numerical study employs direct numerical simulations (DNS) to examine the two-way interactions between freely-moving vaporizing droplets and isotropic turbulence. The droplets will be fully resolved in 3D space and time, i.e. not treated as point particles, and all the scales of the turbulent motion are resolved down to the smallest relevant length- and time-scales (the Kolmogorov scales). The emphasis will be on the two-way exchange of mass, momentum and energy between the vaporizing droplets and the surrounding turbulent gas. The turbulence will be assumed isotropic as a first step before considering turbulent shear flows in future studies.The results of the proposed study will potentially impact efficient utilization of energy. This impact stems from the fact that the vaporization rate is the main controlling mechanism of fuel droplet combustion and that liquid fuels are the most important source of energy for all modes of transportation and will remain as such for the foreseeable future. Understanding the physical details of the vaporization and mixing processes in a turbulent flow is an essential prerequisite to understanding the chemical reaction process and the eventual control/optimization of the energy conversion process. The PI has a record of accomplishment in the field of study and in combining research and teaching, including outreach to undergraduate students and underrepresented students in the sciences.