以計算流體力學方法進行自主式水下無人載具之流體動力分析

IMPLEMENTING HYDRODYNAMIC ANALYSIS OF AUTONOMOUS UNDERWATER VEHICLE BY USING THE CFD METHOD

為探討本實驗室自行開發的自主式無人水下載具，本研究經由計算流體力學的方法來探討自主式無人水下載具在全附屬物下的流體動力特性。在紊流模型的設定上採用SSTk-ω模型來解析流體的邊界層流之模擬，並使用SIMPLEC作為求解器之設置條件。本研究參考DARPASUBOFF的實驗規劃進行一系列拖航試驗，以探討在不同入流角（β）、俯仰角（α）的實驗條件下，以模擬自主式無人水下載具所承受的力及力矩之時序列變化，並同時觀察其縱向垂直流速剖面、不同位置之橫向垂直流速剖面、表面壓力分佈、縱向垂直壓力係數和摩擦係數分佈。

In order to investigate an Autonomous Underwater Vehicle (AUV) established by our laboratory, hydrodynamic characteristics of the AUV with full appendages have been analyzed by Computational Fluid Dynamics (CFD) method. SST k-ω turbulence model was adopted to simulate the boundary layer flows, whereas the Semi-Implicit Method for Pressure Linked Equations-Consistent (SIMPLEC) algorithm was utilized as a solver in the CFD model. Subsequently, a series of numerical simulations with reference to towing tank tests conducted by the DARPA SUBOFF model. The experimental conditions include the drift angle (β) and the pitch angle (α) tests. In the numerical simulation, time histories of forces and moments were firstly calculated. Furthermore, this study presents longitudinal velocity profiles along the meridian planes, cross-sectional velocity profiles at different locations, surface pressure distributions, longitudinal distributions of pressure and friction coefficients along the meridian planes.