CFD Models for Liquid-Phase Chemical Reactors: Validation of PDF and Large-Eddy Simulations Using Stereo PIV and Reactive PLIF Experiments

研究：基于计算流体力学(CFD)的宏观模型有可能改进化工过程工业中的反应堆设计。更好的反应堆设计还可以通过产生毒性较低的副产品来减少污染。许多化学过程涉及快速化学反应，其产物分布受湍流传输的影响。对于这些系统，CFD的有效使用依赖于微观混合模型的开发和验证，这些模型需要在亚网格尺度上描述湍流混合和化学反应之间的复杂相互作用。商业CFD代码在模型开发和验证方面存在缺陷，必须克服这些缺陷，才能充分发挥CFD开发环境友好、商业高效的化学技术的潜力。PI将专注于开发湍流液相化学反应的CFD模型。他们计划使用同步立体粒子图像测速仪(SPIV)和反应性平面激光诱导荧光(RPLIF)技术，在严格控制的操作条件下，获得两种正则反应器几何形状的液体内湍流流场和浓度场的实验数据。在建模方面，他们将基于流动的大涡模拟(LES)和化学物质的概率密度函数(PDF)，开发湍流反应流的CFD模型。这些模型包含定义明确的非闭合项，这些项将从SPIV和RPLIF数据中提取，用于两种典型的湍流流动：受限平面射流和受限突然膨胀平面射流。更广泛地说，在这个项目中获得的知识将提高在使用SPIV和RPLIF在液体湍流中同时测量速度和反应标量统计的测量技术方面的最先进水平。更广泛的影响：私人投资机构从代表性不足的群体中招募学生参与他们的研究已经有很长的历史了。爱荷华州立大学的许多机构范围内的少数民族和妇女招生计划为这些外展活动提供了便利。K-12的学生将被邀请到PI的实验室作为暑期研究实习生工作。减少产品选择性差造成的污染和有毒副产品是开发环境友好、商业高效的生产燃料、材料、化学品和药品的化学技术的关键一步。

Research: Macroscopic models based on computational fluid dynamics (CFD) have potential for improving reactor design in the chemical process industries. Better reactor design can also lead to reducing pollution by producing less toxic byproducts. Numerous chemical processes involve fast chemical reactions for which the product distribution is affected by turbulent transport. For these systems, using CFD effectively depends on the development and validation of micromixing models needed to describe the complex interactions between turbulent mixing and chemical reactions at the sub-grid scale. Commercial CFD codes have shortcomings related to model development and validation that must be overcome before CFD can reach its full potential for developing environmentally benign, commercially efficient chemical technologies. The PIs will focus on developing CFD models for turbulent liquid-phase chemical reactions. They plan to obtain experimental data for turbulent flow field and concentrations fields inside the liquid phase for two canonical reactor geometries under carefully controlled operating conditions using simultaneous stereo-particle-image velocimetry (SPIV) and reactive planar laser-induced fluorescence (RPLIF). On the modeling side they will develop CFD models for turbulent reacting flows based on large-eddy simulation (LES) of the flow and probability density functions (PDF) for the chemical species. These models contain well-defined unclosed terms that will be extracted from SPIV and RPLIF data for two canonical turbulent flows: a confined planar jet and a confined sudden-expansion planar jet. More generally, the knowledge gained in this project will enhance the state of the art in measurement techniques for simultaneous velocity and reacting scalar statistics using SPIV and RPLIF in liquid-phase turbulent flows. Broader Impacts: The PIs have a long history of recruiting students from underrepresented groups to become involved in their research. These outreach activities are facilitated by many institution-wide minority and women recruitment programs at Iowa State University. K-12 students will be invited to work in the PI's laboratory as summer research interns. The reduction of pollution and toxic byproducts caused by poor product selectivity is a critical step towards the development of environmentally benign, commercially efficient chemical technologies for the production of fuels, materials, chemicals and pharmaceuticals.