考慮短波效應之波浪中附加阻力計算

Wave Added Resistance of Ships with the Effects in Short Waves

歷年來，已有許多關於船舶波浪中附加阻力計算之理論散見於相關文獻中。船舶在波浪中之附加阻力，一般均從入射波與船體運動交互作用之二階定常力（second-order steady forces）著手。本文採用二維截片法搭配遠場法為基礎，並輔以短波修正式，提出複合式波浪中增加阻力計算法。在長波部份，以Lin & Reed推導之遠場法理論為基礎，搭配二維截片法（strip method）船舶運動計算之速度勢（velocity potentials）計算船舶在波浪中之附加阻力；在短波中之波浪的作用力之計算，主要為波浪之反射（reflection）效應，本文則採用Fuji & Kuroda之短波計算法配合經由試驗資料修正之經驗式計算之。本文分別以不同CB值之貨櫃船、油輪以及單體高速船為例，計算其在波浪中之附加阻力，並與模型試驗之量測結果比較，驗證本法之可行性。 Several theoretical approaches to compute the added resistance in waves had been developed in the past. In general, this force is presumed to be the second-order steady forces. In this paper, a hybrid approach is proposed, and validation in various hull types is carried out. The far-field method based on the Lin & Reed's theory is adopted with velocity potentials obtained from linear two-dimensional strip theory. In addition, Fuji & Kuroda's empirical formulation is adopted in the estimation of added resistance short waves. The works are done in various benchmarks, including a container vessel, an oil tanker, and a mono-hull fast ship to validate the proposed approach. By comparing with experimental data for various ship types, the accuracy of proposed hybrid approach is identified, and provides confidence to potential user.