Collaborative Research: Unraveling the Spatiotemporal Dynamics of Inertio-Elastic Turbulence using Measurements and Data-Infused Simulations

合作研究：利用测量和数据注入模拟揭示惯性弹性湍流的时空动力学

• 批准号: 2027875
• 负责人: Tamer Zaki
• 金额: $ 24万
• 依托单位: Johns Hopkins University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2027875&HistoricalAwards=false
• 关键词: Collaborative; Research; Unraveling; Spatiotemporal; Dynamics

When polymers are added to a solvent, even in very dilute solutions, they markedly change the behavior of the fluid in intriguing ways, such as reducing the drag force of flow past objects. Polymer-induced drag reduction in marine transport applications can result in 20-25% decrease in frictional energy losses and can thus have a major impact on society in the form of reduced fuel consumption and carbon dioxide emissions. However, the changes induced in the time-varying three-dimensional fluid dynamics are often counter-intuitive and poorly understood. In some configurations, the polymeric solution can introduce new flow instability mechanisms that would not be possible in typical fluids; yet in other regimes, the same forces can also have the seemingly opposite effect of mitigating the energetic eddying motions of turbulence. Direct imaging of the evolution of turbulent flow structures is needed, and it requires a technique with very high resolution and sensitivity. The research plan to achieve this goal is tightly coupled with an education and outreach plan that includes both curriculum development and supplemental lectures and interactive lab demonstrations for Engineering Innovation through summer programs for high-school and college-level STEM students at both universities.The research involves detailed experiments using a unique imaging system to probe how a polymeric jet injected into a surrounding Newtonian fluid becomes unstable. These visualizations will enable a detailed characterization of the mixing between the polymeric jet and the surrounding fluid and the amplification rate of jet instability. The results from the experiments will be complemented by first-of-their-kind measurement-infused simulations of the same configuration. By directly integrating the measurements into the simulations, computations will probe the exact same flow and provide all the additional details that cannot be measured directly in the laboratory. The coupled results from both the experiments and simulations will provide an unprecedented view of the mechanisms through which polymer solutions alter turbulent flow instabilities. Ultimately, such insights will explain how molecular parameters such as chain extensibility and flow elasticity control polymer drag reduction and help guide selection of novel biopolymer sourced additives that can serve as cheap and environmentally friendly substitutes for traditional drag reduction agents such as synthetic polymers derived from hydrocarbon resources.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

当聚合物添加到溶剂中时，即使是在非常稀的溶液中，它们也会以有趣的方式显着改变流体的行为，例如减少流过物体的阻力。海洋运输应用中聚合物诱导的减阻可以使摩擦能量损失减少 20-25%，从而以减少燃料消耗和二氧化碳排放的形式对社会产生重大影响。然而，时变三维流体动力学中引起的变化通常是违反直觉的并且人们知之甚少。在某些配置中，聚合物溶液可能会引入新的流动不稳定机制，这在典型流体中是不可能的。然而，在其他情况下，相同的力也可能产生看似相反的效果，即减轻湍流的高能涡流运动。需要对湍流结构的演化进行直接成像，并且需要具有非常高的分辨率和灵敏度的技术。实现这一目标的研究计划与教育和推广计划紧密结合，其中包括课程开发、补充讲座以及通过暑期项目为两所大学的高中和大学 STEM 学生进行工程创新的交互式实验室演示。涉及使用独特的成像系统进行详细的实验，以探究注入周围牛顿流体的聚合物射流如何变得不稳定。 这些可视化将能够详细表征聚合物射流与周围流体之间的混合以及射流不稳定性的放大率。 实验结果将通过相同配置的首个注入测量的模拟来补充。 通过直接将测量结果集成到模拟中，计算将探测完全相同的流量，并提供无法在实验室直接测量的所有附加细节。 实验和模拟的耦合结果将为聚合物溶液改变湍流不稳定性的机制提供前所未有的视角。 最终，这些见解将解释分子参数（例如链延伸性和流动弹性）如何控制聚合物减阻，并帮助指导选择新型生物聚合物来源的添加剂，这些添加剂可以作为传统减阻剂（例如源自碳氢化合物的合成聚合物）的廉价且环保的替代品该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Spatiotemporal signatures of elastoinertial turbulence in viscoelastic planar jets

粘弹性平面射流中弹性惯性湍流的时空特征

• DOI: 10.1103/physrevfluids.8.064610
• 发表时间: 2022-07-21
• 期刊: Physical Review Fluids
• 影响因子: 2.7
• 作者: Sami Yamani;Yashasvi Raj;T. Zaki;G. McKinley;Irmgard Bischofberger
• 通讯作者: Irmgard Bischofberger

Spectral Universality of Elastoinertial Turbulence

弹性惯性湍流的谱普适性

• DOI: 10.1103/physrevlett.127.074501
• 发表时间: 2021-08
• 期刊: Physical Review Letters
• 影响因子: 8.6
• 作者: Yamani, Sami;Keshavarz, Bavand;Raj, Yashasvi;Zaki, Tamer A.;McKinley, Gareth H.;Bischofberger, Irmgard
• 通讯作者: Bischofberger, Irmgard