以不同計算方法研究雙體船的耐波性能

INVESTIGATION OF THE SEAKEEPING PERFORMANCE OF TWIN HULL VESSELS BY DIFFERENT COMPUTATIONAL METHODS

本文採用不同的計算方法進行計算並分析穿浪型高速雙體船的耐波性能，其目的是研究雙體船的水動力特性。計算上採用勢流方法和RANS方法並進行結果比較。比較不同方法的計算結果有兩個目標。第一個是用於驗證目的，並確保計算的準確性；其次，通過計算結果與實驗數據的比較，不僅顯示了數值的誤差，且揭示了每種方法的不同特徵。從基於驗證及確認分析的結果來看，其證明了RANS方法在耐波性方面有著更好的預測能力。

The seakeeping performances of wave piercing high speed catamaran (CAT-I) was computed and analyzed by different computational methods in this paper. The purpose is to investigate the hydrodynamic characteristics of twin hull vessels for installing the motion suppressing devices such as RCS (riding control system). The potential flow method and viscous flow RANS (Reynolds Averaged Navier-Stokes) method were used for computations. The comparisons of results from different computational methods serve two objectives. The first one is for the verification purpose to ensure the accuracy of computations. Secondly, by comparing results with experimental data, the results not only show the numerical errors, but also reveal the different features of each method. For example, the viscous and nonlinear effects of forces and flow field can thus be identified. From the preliminary results, the comparisons between numerical predictions and experimental data show a good agreement for seakeeping performances, as well as some differences near the resonance frequencies. Overall, the viscous flow RANS method demonstrates better predictions in seakeeping based on the verification and validation analysis.