IDR: Phononic Surfaces for Flow Control

IDR：用于流量控制的声子表面

• 批准号: 1131802
• 负责人: Mahmoud Hussein
• 金额: $ 51.75万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-01 至 2015-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1131802&HistoricalAwards=false
• 关键词: IDR; Phononic; Surfaces; Flow; Control

This Interdisciplinary Research project presents a new concept for surfaces interacting with fluids - flexible surfaces that can be designed to hydroelastically or aeroelastically interact with boundary-layer flow in a favorable manner leading to reduction of drag forces. The basic idea, which is inspired by condensed matter physics, is to have a periodic lattice structure at the inner core of the surface, hence the phrase phononic surface. The surface will be primarily designed to delay laminar-to-turbulence transition and separation, and also to cause drag reduction for fully developed turbulent flow. Other functions that can be simultaneously realized are reduction of overall vibrations and structural noise emission. The research plan involves investigation of an efficient, systematic and integrated methodology for modeling, analysis and design of the proposed phononic surfaces. For the periodic lattice unit cell band structure calculation, a novel and efficient computational scheme based on modal analysis will be utilized. Specialized genetic algorithm operators will be created for the unit cell optimization. Direct numerical simulation of the flow and the elastic wave motion in the surface will be carried out. The unit-cell design will be performed independently of the full coupled solid-fluid simulations thus providing crucial computational savings. The interdisciplinary nature of the research, at the cross-roads of dynamical systems, condensed matter physics and fluid dynamics will enrich the various aspects of the planned research. Elucidating the nature of the interaction between the dispersive periodic waves in and beneath the solid surface and the nonlinear and unstable fluid waves will constitute a new discovery involving fundamental physical phenomena. The subsequent utilization of this knowledge promises to open a new direction in flow control. For streamlined ships and aircrafts, or vehicles in general, the proposed drag-reduction concept will bring about substantial improvements in fuel efficiency and hence economic and environmental benefits. Gains to the performance of turbines of different sorts could also be realized.

这个跨学科研究项目提出了与流体相互作用的表面的新概念——柔性表面，可以设计成以有利的方式与边界层流进行水弹性或气动弹性相互作用，从而减少阻力。其基本思想受到凝聚态物理学的启发，是在表面的内核处具有周期性晶格结构，因此称为“声子表面”。该表面的主要设计目的是延迟层流到湍流的过渡和分离，并且还可以减少充分发展的湍流的阻力。可以同时实现的其他功能包括减少整体振动和结构噪音排放。该研究计划涉及对所提出的声子表面进行建模、分析和设计的高效、系统和集成方法的研究。对于周期晶格晶胞能带结构的计算，将采用基于模态分析的新颖且高效的计算方案。将为晶胞优化创建专门的遗传算法算子。将进行表面流动和弹性波运动的直接数值模拟。晶胞设计将独立于完全耦合的固液模拟进行，从而节省重要的计算量。该研究的跨学科性质，处于动力系统、凝聚态物理和流体动力学的十字路口，将丰富计划研究的各个方面。阐明固体表面内部和之下的色散周期波与非线性和不稳定流体波之间相互作用的本质将构成涉及基本物理现象的新发现。随后对这些知识的利用有望开辟流量控制的新方向。对于流线型船舶和飞机，或者一般的车辆来说，所提出的减阻概念将带来燃油效率的大幅提高，从而带来经济和环境效益。还可以实现不同类型涡轮机性能的提高。