Decomposition of the Unsteady Wave Patterns for Bessho form Translating-Pulsating Source Green Function

作     者：XIAO Wenbin DONG Wencai 

作者机构：Department of Naval Architecture Naval University of Engineering 

出 版 物：《Journal of Ocean University of China》 (中国海洋大学学报（英文版）)

年 卷 期：2014年第13卷第5期

页      面：771-776页

核心收录：

学科分类：07[理学] 0707[理学-海洋科学] 

基　　金：financial support from the National Natural Science Foundation of China under Grant No. 50879090 the Key Program of Hydrodynamics of China under Grant No.9140A14030712JB11044 

主　　题：translating-pulsating source unsteady wave patterns stationary-phase analysis near-field flow component wave component 

摘      要：In order to interpret the physical feature of Bessho form translating-pulsating source Green function, the phase function is extracted from the integral representation and stationary-phase analysis is carried out in this paper. The complex characteristics of the integral variable and segmentation of the integral intervals are discussed in m complex plane. In θ space, the interval [-π/2+φ,-π/2+φ-iε] is dominant in the near-field flow, and there is a one-to-one correspondence between the real intervals in m space and the unsteady wave patterns in far field. If 4τ1(τ is the Brard number), there are three kinds of propagation wave patterns such as ring-fan wave pattern, fan wave pattern and inner V wave pattern, and if 04τ1, a ring wave pattern, an outer V and inner V wave pattern are presented in far field. The ring-fan or ring wave pattern corresponds to the interval [-π+α,-π/2+φ] for integral terms about k2, and the fan or outer V wave pattern and inner V wave pattern correspond to [-π+α,-π/2) and(-π/2,-π/2+φ] respectively for terms about k1. Numerical result shows that it is beneficial to decompose the unsteady wave patterns under the condition of τ≠0 by converting the integral variable θ to m. In addition, the constant-phase curve equations are derived when the source is performing only pulsating or translating.