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

尽管最近在数值模拟方面取得了进展，但仍然需要在控制良好的实验室环境中使用机械产生的波来研究许多波现象。传统上，几乎是普遍的，波浪是由一个在流体柱中机械振荡的运动活塞或襟翼在水箱中产生的。这些系统的好处是它们相对简单，并且拥有大量的用户体验和知识基础。缺点主要在于物理限制；特定设计的造波器针对特定的波，如长或短，线性或非线性。此外，这些传统的造波系统，耦合波和流，甚至进一步分层，开始需要拼凑修改，可能不适合基础科学研究。这个探索性项目将开发和实施一个新的实验概念，使用一系列计算机控制的水射流来“完全”控制波浪、电流和分层。这有可能从根本上改变科学家和工程师研究海洋流动的方式。使用这种技术的小型储罐，例如在这个项目中建造的储罐，相对便宜，并且该概念的广泛扩散是一个目标。开发的设计图纸和控制系统配置将通过在线方式完全公开和分发。在未来的某个时候，波浪和流动设施可能会完全取消墙壁和造波器，取而代之的是在四面包裹着蜂窝状的流动入口，所有这些入口都是单独和同时控制的。为了解决多尺度、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情况。这个“平台”被称为射流阵列造波器（JAW），旨在取代传统的造波器概念，其体积过于简单，采用一系列独立的流动系统，每个系统将水流输送到特定的垂直水平。该流动输送方法包括一个充满水的圆柱体，该圆柱体具有电机控制的活塞，将水推出和拉入该圆柱体。该系统具有非常精确的流量控制，因为电机可以接受非常高的频率输入，并且可以以合理的成本提供足够的扭矩来满足大多数需求。从气缸流出的流量是直接控制的，因为它是一个简单的质量守恒计算。该颚是同样精确的活塞的位移是线性相关的时间积分的电机转数。因此，气缸概念在精度和控制方面比其他系统具有明显的优势，这是颚系统最重要的组成部分。与现有的造波器系统相比，JAW在物理应用空间上有两个主要优势。首先是波数倍深度的应用范围非常广；人们可以同时运行波和流，这两种成分是通过同一个系统产生的。JAW系统的第二个主要优点是产生同步波、流和分层流，包括内波。这是该系统最独特的潜力，并应提供研究现有系统无法达到的复杂海洋学过程的机会。

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.