摘要
摘要 水下滑翔機是一種長程、長時間的新式自主式水下載具(Autonomous Underwater Vehicle ，AUV)，藉著主翼提供滑翔時所需的升力，靠著浮力引擎 的吸水或排水，控制重力浮力差，並配合內部的移重裝置，達到操控水下滑翔 機的運動的效能。 而流體動力係數對於水下滑翔機的運動、操控性能，有著決 定性的影響。因此，如何正確的分析或估算出流體動力係數，對於掌握水下滑 翔機動態性能是非常重要的。 本研究以泛用型計算流體力學軟體FLUENT，先進行對4621 軸對稱潛體 的驗證計算，並與DTNSRDC 以及NTU 的模型實驗結果做比對，在確認了計 算所使用的數值方法與網格佈置方式、數量的妥適性之後，本研究再進行對水 下滑翔機在不同攻角下低速穩態滑翔時，其周圍流場的分析與流體動力的計 算。本研究亦同時利用此CFD 計算結果，檢討DATCOM 經驗公式所估算出的 昇力、阻力係數在工程應用上的適用性。
並列摘要
Autonomous Underwater Glider (AUG) is a novel kind of autonomous underwater vehicle that has very long range and very long duration. An underwater glider is driven by buoyancy engine which could change net buoyancy by expelling or infusing water, and moving weight. Since the dynamic characteristics of an underwater glider depend on its hydrodynamic coefficients significantly, it’s important to analyze or estimate the hydrodynamic coefficients with accuracy enough. In the present study, the CFD commercial software FLUENT was used to analyze the flow field and determine the hydrodynamic coefficients of an underwater glider. In order to confirm the numerical approaches and mesh arrangement in determining the hydrodynamic coefficients of an underwater glider are appropriate, a comparison calculation was carried out firstly using the experimental data of 4621 axial symmetric submerged body tested by DTNSRDC and NTU. Then the same numerical approaches and mesh arrangement are applied to an underwater glider to determine its hydrodynamic coefficients. Estimation using DATCOM database is also examined by comparing with the CFD results using FLUENT.