LES Subgrid Modeling of Liquid-Gas Phase Interface Dynamics

该奖项是根据《2009年美国复苏和再投资法案》(公法0853627-5)资助的。许多液/气两相流动都涉及到拓扑变化，其中液体的雾化受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都是至关重要的，但目前还不存在根据第一原理得出的预测模型。利用大涡模拟(LES)开发雾化流动的预测模型是本研究的目的。由于雾化过程中的相界面动力学并不遵循级联过程，因此设计了一种新的方法来确定包含相界面动力学的大涡模拟公式中的非闭合项。这种方法基于多尺度分解，结合了直接数值模拟和大涡模拟的特点，内在地结合了不同作用力之间的相互作用和竞争，以及作用在多个长度和时间尺度上的雾化机制。虽然该项目的重点是液/气界面，但计划中的方法也可以应用于其他可能遵循或可能不遵循级联过程的类似界面的薄型结构，例如预混和部分预混火焰前锋。项目中开发的所有求解器和模型都将免费提供。基于黑猩猩的范例，适应其他研究人员的代码很简单，因此确保了该项目结果的广泛传播。这种用于雾化的高效、可预测的LES方法有可能启动一种变革性的、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明显低于实验研究。这项研究将把研究结果纳入一个新的交叉列出的研究生/高级本科课程，该课程将由PI开发，关于多相流。课程中开发的项目将帮助招收本科生参加REU项目，这些项目将侧重于支持和加强高中外展计划。研究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来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。然后，最佳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，并将使用在该项目中与REU学生一起开发的模型和工具进行数值分析。高中生将参观亚利桑那州立大学生物推进实验室，并通过两个远程控制的网络摄像头监控教室里的实验。

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.