双体气垫船主要要素对兴波性能的影响

The Effect of Parameters of Air Cushion Assisted Catamaran(ACAC) on Wavemaking Characteristics

本文用线性化水波理论，建立了双体气垫船兴波的数学模型。在两片体的中心面和压力面上分布Ｋｅｌｖｉｎ源，由于两片体之间及片体与压力面之间的相互干扰较小［４］，故未予考虑，当片体为方尾时用虚长度方法进行处理，并用帐篷函数表达片体及压力面分布，使计算简便。并以此数学模型为基础，计算了双体气垫船的远场兴波波形，计算结果与数学船模［４］及实用双体气垫船模（ＳＥＳ４）的试验结果吻合较好，这证明了用此数学模型计算双体气垫船兴波是可能的。本文还以ＳＥＳ４船模为基础，系列地变化双体气垫船的几个主要要素，如片体间距、气垫压长比、气垫长宽比及值，探讨了主要要素变化对双体气垫船兴波性能的影响。

The numerical model for wave profile of ACAC presented in this paper is hased upon linedrized waterwave theory. Kelvin sources are distributed over the air cushion plane and center planes of the demihulls, the interference effects among the waves due to the demihulls and the air cushion are disregarded, being insignificant aspointed out in [4], Tent Functions are used to represent both the demihulls and the cushion pressure, and fictitiouslength is added to cope with the transom stern case.Applying this method, the calculations are made for the far field wave profiles of Wigley Hull and a practicalACAC (SES4). The calculated results of them are in very good agreement with the measurements from tests, showingthe posibility of applying present method to ACAC. Also investigated in this paper are the effects on wavemakingcharacteristics by changing the ship's particulars, such as the separation distance of demihulls, the air pressure length ratio, the length-beam ratio and the air cushion equivalent displacement ratio etc.