以計算流體力學分析不同海象下小艇進入運輸船之安全性

THE SAFETY OF DINGHY ENTERING TRANSPORT SHIPS UNDER DIFFERENT SEA STATES BY CFD ANALYSIS

本研究藉由勢流理論計算程式，計算不同海象下母船（參考USS Harpers Ferry，LSD-49）之船體運動，再結合黏性流理論，由Fluent模擬小艇進入塢艙時之運動姿態，透過非線性船舶運動模型與波浪外力動態模擬，分析不同海象下船舶間相對運動之碰撞可能性。
本文所提出之計算方法，針對不同海象、波向、船舶航速皆能依據值勤條件彈性設定，並根據模擬結果，提供最佳安全之值勤建議（頂浪低速進塢），對於不良海象提出任務預警（順浪高速進塢），避免突發之船體碰撞事故；此方法亦可用於不同船舶，分析母船搭載小艇之適用性，提供造船廠在設計、建造階段之建議，生產安全與任務功能兼具之船舶。

This study uses the potential flow theory to calculate the hull motion of the transport ship under different sea states. Combined with the CFD method, the software Fluent calculates the hull motion of the dinghy when it enters the dock. Through the nonlinear ship motion model and the wave external force dynamics simulation, the study analysis the collision possibility of the relative motion between two hulls under different sea states.
The calculation method proposed in this study can be flexibly set according to the duty conditions for different sea states, wave directions and ship speeds. Based on the simulation results, it provides the best and safe duty advice (head sea and low-speed docking), and the task warnings (following sea and high-speed docking) to avoid sudden ship collisions. The method can also be used for different ships, to analyze the suitability of the transport ship to carry dinghies, and to advise the shipyards to build ships of combined safety and mission functions during the design and construction stages.