低速迷你型水下載具之阻力量測與數值模擬

Drag Estimation of a Towed Miniature Underwater Vehicle at Low Speeds by Experiment and Numericalsimulation

本研究提出一種簡易、低成本之低雷諾數的阻力量測方法，以迷你型水下載具為測試模型，分別進行理論分析、實驗與數值模擬驗證。在定拖曳力之阻力量測方面，有單邊拖曳阻力測定法與對邊拖曳阻力測定法兩種，測試體為球體與特定迷你型水下載具，並於小型拖曳水槽內使用兩種不同黏滯性之工作流體。本研究並使用CFD技術進行模擬驗證，數值結果顯示本量測方法用於低雷諾數載具航行之阻力量測的可信度。文中藉由所量得的速度與阻力的關係，歸納出相關數學模式；而本文內載具的雷諾數範圍可低至約100至500間。 An experimental methodology, which is simple and cost effective, has been proposed to measure the drag of moving miniature underwater vehicles with low Reynolds numbers. The proposed fixed-propulsion experiment includes the drag measurement of one-side towed body as well as two-side towed body. The test body is a sphere or an underwater vehicle with two kinds of working fluids, indicating different viscosities, in the small towing tank Moreover, the CFD technique was used to analyze the flow field. The comparisons between CFD and experiment have shown the feasibility of the present experimental methodology. The correlations of velocities versus drags of test bodies have been obtained, with cruising Reynolds numbers ranging from about 100 to 500 for the present specific underwater vehicle.