三型船艇人員暈船率分析

A STUDY ON THE PREDICTION OF THE MOTION SICKNESS INCIDENCE OF THREE CRAFTS AT SEAS

本研究使用二維截片理論計算三型離島交通船於規則波中運動反應振幅算子及相位角，經由加速度公式計算船上不同位置之垂向加速度，分析影響垂向加速度之因素。使用Bretschneider波譜計算得三型船艇於非規則波中之垂向加速度運動反應統計值，並與海上試俥資料進行驗證，結果顯示理論計算合理。應用ISO 2631-1（1997）人員暈船率標準分析模式，本文系列分析並探討影響人員暈船率的主要因素，計算結果顯示：影響暈船率的主要因素有船舶尺寸、有義波高、波週期、船速、航向角、座位位置及航行時間。船舶越大，垂向加速度運動量越低，則人員暈船率較低，但同時必須探討船舶垂向加速度反應之共振區，是否與暈船率加權參數值較大之對應頻率接近，若越接近，則人員暈船率反而越大。船艇之航況在有義波高低，船速低，艉浪航況航行，座位置靠近縱向重心，及航行時間越少，都能有效降低暈船發生。 The Response Amplitude Operators (RAO) and phase angles of three crafts in regular waves are calculated by the two-dimensional strip theory in this study. The vertical accelerations of various seats for three crafts have been analyzed by through the absolute motion equation. In irregular wave predictions, the Bretschneider spectrum is employed to evaluate motion responses of three crafts in different conditions. The validation work has been carried out by comparing the numerical predictions and data obtained from sea trial. The comfort assessments, Motion Sick-ness Incidences (MSI), are based on the ISO 2631-1 (1997) standard with the hydrodynamic analysis for determining the acceleration levels in different locations on three vessels in waves. The effects of ship displacement, significant wave height, wave period, ship speed, seating location, wave heading and duration of motion exposure on seasickness are discussed. Based on the numerical investigation, the lower significant wave height and ship speed, seating location around the center of gravity and stern wave condition, shorter duration of motion exposure on sea-sickness will result the small MSI for the crafts. However, the resonance of the vertical accelerations should be examined with the encounter periods of weighting factor of MSI for different ship displacements. The large ship dis-placement may result the higher MSI for ships travelling in waves due to the resonance effects.