信息熵控制的海洋流线自适应步长算法研究  

Research on adaptive step size algorithm of marine streamline controlled by information entropy

作　　者：李忠伟[1] 焦方涛 李永[1] 曾伟 杨俊钢 崔伟 Li Zhongwei;Jiao Fangtao;Li Yong;Zeng Wei;Yang Jungang;Cui Wei(College of Oceanography and Space Informatics,China University of Petroleum,Qingdao 266580,China;First Institute of Oceanography,Ministry of Natural Resources,Qingdao 266061,China)

机构地区：[1]中国石油大学(华东)海洋与空间信息学院,山东青岛266580 [2]自然资源部第一海洋研究所,山东青岛266061

出　　处：《海洋学报》2024年第12期100-110,共11页

基　　金：国家自然科学重点基金(62231028)。

摘　　要：海洋流场的流线构造与放置对于认识和理解海洋流场具有重要意义。在流线绘制过程中,积分步长的选择至关重要,能够直接影响流线放置效果。固定步长算法由于无法适应曲率不断变化的情形往往不被采用,以往自适应步长流线算法存在自由度低以及多尺度适用性差的问题。针对上述问题,本文首次将信息熵引入到步长计算中,提出了信息熵控制的海洋流线自适应步长算法。该算法首先通过计算流场信息熵得到熵场,然后依据熵值大小将流场划分为高熵区域和低熵区域,并为每个积分点赋予新的步长,使得流场可以根据变化剧烈程度自适应调整步长大小,即高熵区域(变化剧烈的区域)步长较小,低熵区域(变化平缓的区域)步长较大。实验结果表明,本文算法能够显著增加变化剧烈区域的积分点数目和流线条数,更好地绘制特征处的流线细节,同时在不会影响放置效果的前提下减少了非重要区域的积分点数目和流线条数以提高计算效率,相比以往自适应步长算法显著提高了步长调节的自由度以及尺度适用性,可以应用于不同尺度的海洋流场。The streamline construction and placement of the marine flow field is of great significance for recognizing and understanding the marine flow field.In the process of streamline drawing,the selection of integration step is very important,which can directly affect the effect of streamline placement.The fixed step size algorithm is often not used because it cannot adapt to the changing curvature.The previous adaptive step size streamline algorithm has the problems of low degree of freedom and poor multi-scale applicability.In view of the above problems,this paper introduces information entropy into the step size calculation for the first time,and proposes an adaptive step size algorithm of marine streamline controlled by information entropy.Firstly,the entropy field is obtained by calculating the information entropy of the flow field,and then the flow field is divided into high entropy region and low entropy region according to the entropy value,and each integration point is given a new step size,so that the flow field can adaptively adjust the step size according to the intensity of change,that is,the step size of the high entropy region(the region with sharp change)is smaller,and the step size of the low entropy region(the region with gentle change)is larger.The experimental results show that the proposed algorithm can significantly increase the number of integration points and streamlines in the rapidly changing region,better draw the details of the streamline at the feature,and reduce the number of integration points and streamlines in the unimportant region without affecting the placement effect to improve the computational efficiency.Compared with the previous adaptive step size algorithm,the proposed algorithm significantly improves the degree of freedom of step size adjustment and the scale applicability,and can be applied to different scales of marine flow field.

关 键 词：海洋流场 信息熵 自适应步长 流线放置 数值积分 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]