串列式雙振動翼之流體動力實驗分析

Abstract

水下滑翔機一般是利用浮力引擎調節重力浮力差並藉由機翼的升力使載具產生斜向下潛或上浮的運動，但不具備水平運動的能力。本研究是為了在不影響滑翔的前提下擴展水下滑翔機的水平運動性，提出利用串列式雙振動翼來做為仿生助推器之構想，並設計與製作試驗機構，在水槽中進行一系列的試驗，探討其水動力性能。 本研究探討串列式雙振動翼的振動振幅、頻率和相位差對於水動力性能之影響，結果顯示前後振動翼之間的相位差對於推力有顯著影響，但其推力效果並不如預期，而有待進一步的改進。本研究也確認了CFD軟體”FLUENT”可做為評估本設計的工具，後續將持續運用”FLUENT”及本研究所建置的試驗裝置進一步改進可做為水下滑翔機助推器的設計。

An underwater glider is propelled by a buoyancy engine to adjust the difference between buoyancy and weight, combining with the lift induced by the wing. In general, an underwater glider can ascend or descend obliquely, but has no capability to move horizontally. In view of the fact that an underwater glider is lack of horizontal mobility, a concept of booster with two oscillating foils in series is proposed in the present study to enhance the horizontal mobility without disturbing gliding. A test apparatus is established and a series of tank tests are carried out for clarifying its hydrodynamic characteristics. The effects of amplitude, frequency and phase angle between the two oscillating foils to the hydrodynamic forces are investigated. It is found that the phase angle influences the propulsion force significantly, but the propulsion performance of the proposed design is not as good as expected. It needs to be modified for improving the performance. In addition, the CFD software “FLUENT” has been applied for comparison, and its validity as a tool to evaluate the design has also been confirmed. Therefore, the CFD tool “FLUENT” and the test apparatus established in the present study will be applied continuously in the future work to refine the design of a booster for underwater gliders.