LES Subgrid Modeling of Liquid-Gas Phase Interface Dynamics

CBET - 0853627 Herrmann，Marcus 该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。许多液体/气体两相流涉及拓扑变化，其中液体的雾化由相界面的动力学控制。虽然雾化在从能量转换到药物喷雾的许多技术应用中是至关重要的，但目前不存在来自第一原理的预测模型。本研究的目标是使用大涡模拟（LES）开发雾化流的预测模型。由于在雾化过程中的相界面动力学似乎不遵循级联过程，一种新的方法计划确定的LES制定涉及相界面动力学的未封闭项。这种方法，基于多尺度分解，结合了直接数值模拟（DNS）和LES的功能，内在地结合了不同的力量和雾化机制之间的相互作用和竞争作用在多个长度和时间尺度。虽然该项目的重点是液体/气体接口，计划的方法可以应用于其他薄，接口状的结构，可能会或可能不会遵循级联过程，如预混和部分预混火焰前锋。该项目中开发的所有求解器和模型都将免费提供。基于CHIMPS模式，适应其他研究人员的代码是直截了当的，从而确保广泛传播该项目的结果。这种高效的、预测性的LES雾化方法有可能开创一种变革性的、大胆的新设计理念，因为使用LES方法进行预选可行性研究的成本显著低于实验研究。这项研究将把结果纳入一个新的交叉上市的研究生/高级本科课程，由PI开发的多相流。在课程中开发的项目将有助于招募本科生到REU项目，将重点放在支持和加强高中外展计划。调查人员将与斯科茨代尔联合学区合作，通过设计、测试、分析和优化水管喷嘴，让高中微积分和物理学生参与实验研究，以满足不同的目标。最好的设计将在亚利桑那州立大学的生物推进实验室进行实验分析，并将与REU学生在该项目中开发的模型和工具进行数值分析。高中生将参观ASU生物推进实验室，并通过两个远程控制的网络摄像头监控他们教室里的实验。

CBET - 0853627 Herrmann, Marcus This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). Many liquid/gas two-phase flows involve topology changes, where atomization of the liquid is governed by the dynamics of the phase interface. Although atomization is crucial in many technical applications ranging from energy conversion to pharmaceutical sprays, no predictive models derived from first principle currently exist. Development of such a predictive model using large eddy simulations (LES) for atomizing flows is the objective of this research. Since the phase interface dynamics during atomization do not appear to follow a cascade process, a novel approach is planned to determine the unclosed terms in the LES formulation involving the phase interface dynamics. This approach, based on a multi-scale decomposition, combines features of direct numerical simulations (DNS) and LES that inherently incorporates the interaction and competition between different forces and atomization mechanisms acting on multiple length and time scales. While the focus of this project is on liquid/gas interfaces, the planned methodology can be applied to other thin, interface-like structures that may or may not follow a cascade process, such as premixed and partially premixed flame fronts. All solvers and models developed in the project will be made freely and readily available. Being based on the CHIMPS paradigm, adaptation to other researcher's codes is straightforward, thus ensuring wide dissemination of the project's results. This efficient, predictive LES approach for atomization has the potential to initiate a transformative, bold new design philosophy, because the cost of pre-selection feasibility studies using the LES approach is significantly lower than experimental studies. This study will incorporate results into a new cross-listed graduate/advanced undergraduate course to be developed by the PI on multiphase flows. Projects developed in the courses will help recruit undergraduates into REU projects that will focus on supporting and enhancing a high school outreach program. The investigators will collaborate with the Scottsdale Unified School District to involve high school calculus and physics students in experimental research by designing, testing, analyzing, and optimizing water hose nozzles to meet different goals. The best designs will then be analyzed experimentally in the Biopropulsion Laboratory at ASU, and will also be analyzed numerically with the models and tools developed in this project with the REU students. The high school students will tour the ASU Biopropulsion Laboratory and monitor the experiments in their classrooms via two webcams that are remotely controlled.