本研究主要目的為進行JBC船型在自推狀況下的模擬，並以有無導罩下的模擬結果進行船艉導罩對JBC船型整體阻力和局部流場所造成的影響。所使用的軟體為開源軟體OpenFOAM 9，不考慮船隻在水中之俯仰及下沉情形，測試條件為滿載吃水和設計船速，設定船模速度為1.179m/s，並對照T2015(Tokyo 2015 A Workshop on CFD in Ship Hydrodynamics)研討會網站中日本NMRI(National Maritime Research Institute)之實驗數據對比模擬準確性。
本研究中分做三大階段，分別是裸船阻力有無導罩模擬、單獨螺槳試驗模擬以及自推狀況下有無導罩之模擬，並分別建立疏、中、密三套網格，根據ITTC 75-03-01-01中驗證與確認(Verification and Validation)方法來確保模擬的準確性及可靠性。
在裸船有無導罩的模擬中，證實了導罩對於JBC船型的減阻效果，並在自推狀況下所換算的螺槳前進比之單獨螺槳模擬中取得了良好的結果，且皆通過驗證及確認分析。在自推模擬中，雖無導罩下結果的模擬網格模擬收斂性尚未達成，但在有導罩的結果中具網格收斂性，在有導罩的自推模擬時，密網格整體有最佳的模擬結果，螺槳的推力高估約8.93%、扭矩低估約1.49%，船體之阻力則高估了約13.72%。此外，在中網格之有無導罩自推模擬中，有明確的模擬出導罩對於自推所帶來的影響，在螺槳的推力係數中導罩增進了約11.71%、扭矩係數增進了約4.75%，且降低了約0.49%的船體阻力係數。

The purpose of this study is to simulate the self-propelled JBC (Japan Bulk Carrier) in calm water, and analyze the effect on total hull resistance and local flow field that is caused by the energy-saving stern duct (Energy Saving Device, ESD). The CFD software that we use is OpenFOAM 9, the solver is interFOAM to solve two-phase flow. In this research, sinkage and trim of hull is not considered. The model speed is 1.179m/s, corresponding to the design speed for the full-scale ship.
Three kinds of simulation are designed to make sure the CFD method of the presented work is reliable. In the bare hull resistance simulation with and without duct, we confirm the energy-saving effect from the duct; In the propeller open water test simulation, we obtain great result in the advance ratio that is converted from the propeller thrust of the self-propelled JBC; Finally, in the self-propulsion simulation, we have a fairly good result for the fine mesh with duct: the propeller thrust is overestimated 8.93% and the propeller torque is underestimated 1.49%. The hull resistance is overestimated 13.72%.
Comparing the self-propulsion simulation with and without duct condition for the medium mesh, the propeller thrust and torque predictions are improved by the duct. Also, the duct also reduces the resistance in the self-propelled situation.

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