Development of smart surfaces for flow management/re-arrangement

许多工业产品包含流量系统，其性能影响整体产品能力，特别是与其操作相关的能源成本。能量成本的降低可以主要通过阻力的降低来实现。目前的工作重点是智能表面的发展，将提供一种有效的管理/重新安排的流量。寻求减少表面摩擦层流阻力、通过延迟/加速层流-湍流过渡来影响阻力以及通过重新布置整体流来减少湍流阻力以及湍流产生的表面。对固体界面处流体力学的理解为智能表面的发展提供了基础。流动动力学可以受到例如表面形貌、微机电装置、合成射流、脉冲吹送、等离子体致动器、壁蒸发和加热的影响。所有这些效应都提供了产生流动力（控制驱动）的手段。对使用不同形式的强迫在流动中可以产生的变化的理解形成了这项工作的核心。流动特性的显著变化通常需要使用强强迫。在这项工作中追求使用大量的简单，弱致动器（致动器的蜂拥）。这种致动器只需要很小的能量输入，但只有当它们形成图案时才能有效。正是这种模式的相互作用（而不是单独的致动器）可以产生所需的流量响应。这项工作的目的是研究什么样的模式是水力学上重要的，什么样的流量响应可以实现。基于简单致动器的模式，专注于创建智能表面，将这项工作与任何其他竞争方法区分开来。智能表面具有广泛的应用，例如在航空航天、造船、制药和生物医疗等行业。

Many industrial products contain flow systems whose performance affects the overall product capabilities, especially the energy cost associated with their operation. Reduction of the energy cost may come primarily through the reduction of drag. The present work is focused on the development of smart surfaces that would provide a means for an effective management/re-arranging of flows. Surfaces that reduce the skin friction laminar drag, affect the drag by delaying/accelerating the laminar-turbulent transition and reduce the turbulent drag by re-arranging the bulk flow, as well as turbulence production, are sought. An understanding of the fluid mechanics at the solid interfaces provides a basis for the development of smart surfaces. The flow dynamics can be influenced by surface topography, micro-electro-mechanical devices, synthetic jets, pulsed-blowing, plasma actuators, wall transpiration and heating, for example. All these effects provide means for the creation of flow forcing (control actuation). An understanding of the changes that can be created in the flow using different forms of forcing forms the core of this work. A significant change of flow properties typically requires the use of strong forcing. The use of a large number of simple, weak actuators (a swarming of actuators) is pursued in this work. Such actuators require only a small energy input but can be effective only if they form patterns. It is the interaction of such patterns (rather than the individual actuators) that may produce the desired flow response. The objective of this work is to study what patterns are hydraulically significant and what kinds of flow response can be achieved. The focus on the creation of smart surfaces, based on patterns of simple actuators, differentiates this work from any other competing approaches. Smart surfaces have a wide range of applications, for example in the aerospace, ship-building, pharmaceutical and bio-medical industries, among others.