Synergistically Propelled Ichthyoid (SPI): Dynamics Investigation for Improved Performance

本研究将探讨一种高效、可操作的潜水器的发展所激发的流固相互作用的基本问题。这种潜水器采用了由输送流体射流驱动的鱼状柔性尾巴；射流的推力和摆动尾翼的推力的组合协同推进和操纵潜水器。本研究将融合两个不相关的流固耦合文献——振荡鱼状推进研究和颤振输液管道研究。流体输送管道的文献将扩展到存在于鱼状游泳中的条件：外部流动，空间可变的尾部平台，大变形，快速加速和大旋转。此外，潜水器的加速和旋转将通过改变输送流体的速度来实现；一个需要进一步理论发展的领域。欧拉-伯努利梁理论和弹性理论将用于模拟空间变化的梁输送流体的时间依赖的速度。这些理论研究将辅以数值模拟和实验验证的硬件平台。这种鱼状潜水器采用了一种新颖的推进机制，需要研究在显著加速度和流体力作用下的柔性尾巴。这种潜水器有许多潜在的应用；由于在正常运行过程中，周围的水会被吸入船体，因此它是环境监测、化学传感和水清理作业的理想选择。本研究中开发的方法也将适用于流体结构相互作用中的其他紧急问题，例如大型风力涡轮机叶片的振动控制，以及通过提高对蝙蝠和昆虫飞行的理解来更好地设计扑翼机。在人类中，气道中一个柔性部件的偏转会导致打鼾和睡眠呼吸暂停——更好地了解柔性结构上的液体负荷可以改善治疗和手术治疗。

This research will investigate fundamental problems in fluid-structure interactions motivated by the development of an efficient and maneuverable submersible. This submersible employs a fish-like flexible tail driven by a conveyed fluid jet; the combination of the jet's thrust and that of the oscillating tail synergistically propels and maneuvers the submersible. Two disconnected bodies of fluid-structure interaction literature will be merged in this research - the study of oscillatory fish-like propulsion and the study of fluttering fluid-conveying pipes. The fluid-conveying pipe literature will be extended toward conditions that exist in fish-like swimming: external flow, spatially-variable tail planforms, large deformations, and fast accelerations and large rotations. Furthermore, acceleration and rotation of the submersible will be accomplished by varying the conveyed fluid velocity; an area, which requires additional theoretical development. Euler-Bernoulli beam theory and the theory of elastica will be used to model spatially-varying beams conveying fluid with time-dependent velocity. These theoretical investigations will be complemented by numerical simulations and a hardware platform for experimental verification.This fish-like submersible uses a novel mechanism for propulsion which requires investigation of a flexible tail subjected to significant accelerations and fluid forces. The submersible has many potential applications; since the surrounding water is pulled into the hull during normal operation, it is an ideal candidate for environmental monitoring, chemical sensing and water cleanup operations. The methods developed in this research will also apply to other emergent problems in fluid structure interactions, such as vibration control of large wind turbine blades and better design of ornithopters through improved understanding of bat and insect flight. In humans, deflection of a flexible member in the airway causes snoring and sleep apnea - better understanding of fluid loading on flexible structures could lead to improved therapy and surgical treatments.