Power-saving device for air bubble generation using a hydrofoil to reduce ship drag: Theory, experiments, and application to ships
Power-saving device for air bubble generation using a hydrofoil to reduce ship drag: Theory, experiments, and application to ships
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DOI：
10.1016/j.oceaneng.2014.11.019
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发表时间：
2015-02-01
影响因子：
5
通讯作者：
Murai, Yuichi
中科院分区：
文献类型：
--
作者：
Kumagai, Ichiro;Takahashi, Yoshiaki;Murai, Yuichi
我们开发了一种新的节能装置，利用小气泡来减少船舶船体的阻力。该装置减少了产生气泡所需的能量。该装置由带空气引入器的倾斜水翼组成，当船向前移动时，利用水翼上方产生的低压区域将大气空气驱入水中。我们描述了从简单的流体动力学理论获得的装置原理，并通过在小型拖曳水池中进行的实验，显示了自由表面下的水翼周围的流动行为的基本空气夹带和气泡生成过程。我们还提出了一个半经验的缩放过程，实际应用于全尺寸船舶，以估计该装置实现的净减阻。最后，一系列的全尺寸测试的结果报告，并表明，与正确的操作，我们的设备可以产生5-15%的净功率节省船舶。(C)2014作者爱思唯尔有限公司出版
We have developed a new power-saving device to reduce the drag of a ship's hull using small bubbles. The device reduces the energy required for bubble generation. The device, which consists of angled hydrofoils with air introducers, uses the low-pressure region produced above the hydrofoil as the ship moves forward to drive atmospheric air into the water. We describe the device principles obtained from simple fluid dynamic theory, and, through experiments performed in a small towing tank, show the fundamental air entrainment and bubble generation processes for the flow behavior around a hydrofoil beneath a free surface. We also present a semi-empirical scaling process for practical application to full-size ships to estimate the net drag reduction achieved by this device. Finally, the results of a series of full-scale tests are reported and show that, with correct operation, our device can produce a net power saving of 5-15% for ships. (C) 2014 The Authors. Published by Elsevier Ltd.