Water Wave Scattering by a Nearly Circular Cylinder Submerged Beneath an Ice-cover

作     者：Rumpa Chakraborty Birendra Nath Mandal 

作者机构：Physics and Applied Mathematics Unit Indian Statistical Institute Kolkata 700108 India 

出 版 物：《Journal of Marine Science and Application》 (船舶与海洋工程学报（英文版）)

年 卷 期：2015年第14卷第1期

页      面：69-75页

核心收录：

学科分类：080503[工学-材料加工工程] 0707[理学-海洋科学] 08[工学] 0815[工学-水利工程] 0805[工学-材料科学与工程（可授工学、理学学位）] 0824[工学-船舶与海洋工程] 0802[工学-机械工程] 0801[工学-力学（可授工学、理学学位）] 080102[工学-固体力学] 080201[工学-机械制造及其自动化] 

基　　金：the financial support from CTS Visitors Program  Indian Institute of Technology  Kharagpur during the tenure of which the revision of the paper has been made 

主　　题：water wave scattering ice-cover nearly circular cylinder shape function reflection coefficient transmission coefficient 

摘      要：Assuming linear theory, the two-dimensional problem of water wave scattering by a horizontal nearly circular cylinder submerged in infinitely deep water with an ice cover modeled as a thin-elastic plate floating on water, is investigated here. The cross-section of the nearly circular cylinder is taken as r=a（1＋δC（θ））, where a is the radius of the corresponding circular cross-section of the cylinder, δ is a measure of small departure of the cross-section of the cylinder from its circularity and C（θ） is the shape function. Using a simplified perturbation technique the problem is reduced to two independent boundary value problems up to first order in δ. The first one corresponds to water wave scattering by a circular cylinder submerged in water with an ice-cover, while the second problem describes wave radiation by a submerged circular cylinder and involves first order correction to the reflection and transmission coefficients. The corrections are obtained in terms of integrals involving the shape function. Assuming a general Fourier expansion of the shape function, these corrections are evaluated approximately. It is well known that normally incident wave trains experience no reflection by a circular cylinder submerged in infinitely deep water with an ice cover. It is shown here that the reflection coefficient also vanishes up to first order for some particular choice of the shape function representing a nearly circular cylinder. For these cases, full transmission occurs, only change is in its phase which is depicted graphically against the wave number in a number of figures and appropriate conclusions are drawn.