RII Track-4: NSF: Simulation and Modeling of Turbulent Flow Control via Flow-Dependent Anisotropic Surface Textures

RII Track-4：NSF：通过流相关的各向异性表面纹理进行湍流控制的模拟和建模

• 批准号: 2131942
• 负责人: Wen Wu
• 金额: $ 17.34万
• 依托单位: University of Mississippi
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-02-01 至 2025-01-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2131942&HistoricalAwards=false
• 关键词: RII; Track; NSF; Simulation; Modeling

Flow separation is the phenomenon that occurs when a fluid particle is slowed down and cannot follow the shape of the surface. It has several negative effects on drag and lift that are critical to energy consumption and emissions, aircraft maneuverability, turbine noise, and vibration, etc. The proposed research is motivated by the observation that dermal denticles (tough scales) on shark skin show promising performance in reducing hydrodynamic drag. The ability of sharks’ unique skin in the fish world to dynamically respond to the flow offers a significant performance advantage over current flow control techniques. This fellowship aims at gaining a new fundamental understanding of the causal mechanisms associated with the drag reduction role of shark skin denticles and simultaneously advancing current numerical models for routine industrial design. With the support of an EPSCoR RII Track-4:NSF Fellowship, the PI will learn to simulate and analyze fluid-structure interactions and develop new models for numerical predictive tools through the training at the Center for Turbulence Research (CTR) at Stanford University. The fellowship will strengthen collaboration between the University of Mississippi and Stanford, and promote new economic development opportunities related to aeronautics, aerospace, and naval industries in the mid-south and in the State of Mississippi.The elastic anchoring of shark denticles enables them to bristle when subjected to the reversing separated flow that occurs at the onset of separation, thus hindering local separation. When flow is attached, denticles return to the non-bristled position and form a riblet-like texture to reduce friction drag. This motion leads to a flow-dependent anisotropic (or directional) function of the denticles that indicates a passive, flow-activated separation control technique. Current approaches, designed for stationary surface roughness, are insufficient to understand or predict the complex flows modulated by movable microstructures. The overarching goal of this fellowship is to support the PI’s training and collaborative research at the CTR. The training and research will focus on the cutting-edge fluid-structure interaction simulation methods and the development and validation of a novel wall model for the prediction of complex effects represented by surface microstructures. Specific objectives include: (i) to generate an unprecedented dataset of flows over movable anisotropic microstructures, (ii) to gain a new fundamental understanding about non-linear interactions, (iii) to synthesize the understanding to develop truly predictive models for drag and momentum flux. This RII Track-4:NSF fellowship will expand the PI’s research capacity and transform his career path towards a promising direction in the fluid-solid multi-physics system and reduced-order model development. The unique flow control techniques achieved by the flow-dependent anisotropic microstructure will be highly transformative to many other research areas in aerospace, agricultural, biomedical, energy, and environmental engineering where the application of structures with directional function is needed for the flow control process.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.

流动分离是当流体颗粒放慢速度并且无法遵循表面形状时发生的现象。它对阻力和升降机具有几种负面影响，这对于能源消耗和排放，飞机的可操作性，涡轮噪声和振动等至关重要。拟议的研究是由鲨鱼皮肤皮肤上的皮肤齿（坚韧尺度）在减少流体动力学方面表现出希望的表现的。鲨鱼在鱼类世界中独特的皮肤动态反应流动的能力比当前流量控制技术具有显着的性能优势。该奖学金旨在获得对与鲨鱼皮肤牙齿的拖放作用相关的因果机制的新基本理解，并轻松地推进了常规工业设计的当前数值模型。在EPSCOR RII TRACK-4：NSF奖学金的支持下，PI将学会通过在斯坦福大学的湍流研究中心（CTR）培训来模拟和分析流体结构相互作用，并为数值预测工具开发新的模型。奖学金将加强密西西比大学和斯坦福大学之间的合作，并在中南部和密西西比州促进与航空，航空航天和海军行业有关的新的经济发展机会。鲨鱼齿状的弹性锚固使它们能够在偏置的相反流动时，在分离的情况下，将它们的反向分开流动，因此可以分离出来。连接流动时，牙齿恢复到非毛细管位置并形成类似风险的质地以减少摩擦阻力。该运动导致牙齿的流动依赖性各向异性（或定向）功能，表明一种被动的，流动激活的分离控制技术。目前为固定表面粗糙度设计的当前方法不足以理解或预测由可移动微观结构调制的复杂流。该奖学金的总体目标是支持PI在CTR的培训和协作研究。培训和研究将重点放在尖端的流体结构相互作用模拟方法以及新型壁模型的开发和验证中，以预测表面微观结构代表的复杂效应。特定对象包括：（i）生成一个前所未有的流动性数据集，以移动各向异性微观结构，（ii）获得对非线性相互作用的新基本理解，（iii）综合理解，以开发拖动和动量趋势的真正预测模型。这款RII Track-4：NSF奖学金将扩大PI的研究能力，并将他的职业发展道路转变为流体固体多物理系统和减少阶模型开发的前景方向。通过流动依赖的各向异性微观结构获得的独特流量控制技术将对航空航天，农业，生物医学，能源和环境工程的许多其他研究领域进行高度变化，在该领域中，需要进行流程控制过程的结构应用具有方向功能的应用，这反映了NSF的法定委员会的良好依据，这表明了这一法定委员会的良好影响，并具有良好的依据。

项目成果

A universal velocity transformation for boundary layers with pressure gradients

• DOI: 10.1017/jfm.2023.570
• 发表时间: 2023-08
• 期刊: Journal of Fluid Mechanics
• 影响因子: 3.7
• 作者: Peng E. S. Chen;Wen Wu;K. Griffin;Yipeng Shi;Xiang I. A. Yang