EAGER: Development of a High-Control Jet-Array Wavemaker

EAGER：开发高控制喷射阵列造波器

• 批准号: 1450861
• 负责人: Patrick Lynett
• 金额: $ 5.81万
• 依托单位: University of Southern California
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-15 至 2016-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1450861&HistoricalAwards=false
• 关键词: EAGER; Development; Control; Jet; Array

Despite recent advances in numerical modeling, there is still a need to study many wave phenomena in a well-controlled laboratory setting with mechanically generated waves. Traditionally, and nearly universally, waves are generated in a tank with a moving piston or flap that is mechanically oscillated in a column of fluid. The benefits of these systems are their relative simplicity and a large base of user experience and knowledge. Drawbacks lie mainly in physical limitations; a wavemaker of a certain design targets a specific regime of waves, such as long or short, linear or nonlinear. Further, with these traditional wavemaker systems, coupled waves and currents, and even further stratification, begin to require a patchwork of modifications and may not be suitable for fundamental scientific investigation. This exploratory project will develop and implement a new experimental concept for "complete" wave, current, and stratification control using an array of computer-controlled water jets. This has the potential to fundamentally change the way scientists and engineers study oceanographic flows. Small-scale tanks using this technology, such as the one to be built in this project, are relatively inexpensive, and widespread proliferation of the concept is a goal. The developed design drawings and control system configuration will be completely open and distributed through online means. At some future time, wave and flow facilities may do away with walls and wavemakers completely, being instead wrapped on all sides with a honeycomb of flow portals, all individually and simultaneously controlled. In order to attack multi-scale and multi-fluid physics problems, a new experimental platform to study complex oceanographic situations is required. This "platform", called the jet-array wavemaker (JAW), is meant to replace the traditional concept of a wavemaker, simplistic in its bulk, with a series of individual flow systems, each delivering flow to a specific vertical level. The flow delivery method consists of a water-filled cylinder with a motor-controlled piston pushing and pulling water out of and into the cylinder. This system has extremely precise flow control, as the motors can accept input at very high frequencies and can deliver enough torque to meet most needs at reasonable cost. The flow rate from the cylinder is straightforward to control as it is a simple conservation-of-mass calculation. The JAW is similarly precise as the displacement of the piston is linearly correlated to the time-integration of the motor revolution count. Thus, the cylinder concept has clear advantages over other systems in terms of precision and control, which are the most important components of a JAW system. There are two primary physical-application-space advantages of the JAW over existing wavemaker systems. The first is the very wide range of wavenumber times depth application; one can run simultaneous waves and currents where these two components are generated through the same system. The second primary advantage of the JAW system is the generation of simultaneous waves, currents, and stratified flow, including internal waves. This is the most unique potential of the system, and should present opportunities to study complex oceanographic processes which are unapproachable with existing systems.

尽管数值模拟最近取得了进展，但仍然需要在控制良好的实验室环境中用机械产生的波来研究许多波浪现象。传统上，几乎普遍地，波浪是在带有移动活塞或瓣片的水箱中产生的，该活塞或瓣片在流体柱中机械振荡。这些系统的优点是相对简单并且拥有大量的用户经验和知识。缺点主要在于身体限制；某种设计的造波器针对特定的波型，例如长波或短波、线性波或非线性波。此外，对于这些传统的造波器系统，耦合波和水流，甚至进一步分层，开始需要进行修改，并且可能不适合基础科学研究。该探索性项目将开发并实施一种新的实验概念，使用一系列计算机控制的水射流进行“完整”波浪、水流和分层控制。 这有可能从根本上改变科学家和工程师研究海洋流的方式。使用该技术的小型坦克（例如本项目中要建造的坦克）相对便宜，并且目标是广泛传播该概念。开发的设计图纸和控制系统配置将通过在线方式完全开放和分发。 在未来的某个时候，波浪和流动设施可能会完全废除墙壁和造波器，而是用蜂窝状的流动门户包裹所有侧面，所有这些都单独且同时控制。为了解决多尺度和多流体物理问题，需要一个新的实验平台来研究复杂的海洋学情况。这个“平台”被称为喷射阵列造波器（JAW），旨在用一系列单独的流系统取代传统的造波器概念，其体积过于简单，每个流系统将流传送到特定的垂直高度。流量输送方法由一个充满水的气缸和一个电机控制的活塞组成，将水从气缸中推出或吸入。该系统具有极其精确的流量控制，因为电机可以接受非常高频率的输入，并且可以以合理的成本提供足够的扭矩以满足大多数需求。气缸的流量易于控制，因为它是简单的质量守恒计算。 JAW 同样精确，因为活塞的位移与电机转数的时间积分线性相关。因此，在精度和控制方面，气缸概念比其他系统具有明显的优势，这是 JAW 系统最重要的组成部分。与现有造波器系统相比，JAW 有两个主要的物理应用空间优势。首先是非常广泛的波数乘深度应用；人们可以同时运行波和电流，其中这两个分量是通过同一系统生成的。 JAW 系统的第二个主要优点是同时生成波浪、水流和分层流，包括内波。这是该系统最独特的潜力，并且应该为研究现有系统无法实现的复杂海洋学过程提供机会。