地球信息科学学报 ›› 2017, Vol. 19 ›› Issue (2): 161-166.doi: 10.3724/SP.J.1047.2017.00161

• 地球信息科学理论与方法 • 上一篇    下一篇

基于光滑粒子流体动力学算法的海浪建模仿真研究

李婷1(), 季民1,**(), 靳奉祥2, 张静1, 孙勇1   

  1. 1. 山东科技大学测绘科学与工程学院,青岛 266590
    2. 山东建筑大学,济南 250101
  • 收稿日期:2016-02-18 修回日期:2016-08-09 出版日期:2017-02-28 发布日期:2017-02-17
  • 通讯作者: 季民 E-mail:liting_sdust@126.com;jamesjimin@126.com
  • 作者简介:

    作者简介:李婷(1982-),女,山东聊城人,博士生,主要从事海洋时空数据建模及可视化研究。E-mail: liting_sdust@126.com

  • 基金资助:
    国家自然科学基金项目(41471330);国家自然科学基金青年科学基金项目(41401439);高等学校博士学科点专项科研基金项目(20113718110001)

Research on Ocean Wave Simulation Based on the Method of Combining Smoothed Particle Hydrodynamics with Marching Cubes Algorithm

LI Ting1(), JI Min1,*(), JIN Fengxiang2, ZHANG Jing1, SUN Yong1   

  1. 1. Geomatics College, Shandong University of Science and Technology, Qingdao 266590, China
    2. Shandong Jianzhu University, Jinan 250101, China
  • Received:2016-02-18 Revised:2016-08-09 Online:2017-02-28 Published:2017-02-17
  • Contact: JI Min E-mail:liting_sdust@126.com;jamesjimin@126.com

摘要:

针对传统海浪建模方法中存在海洋表面真实感差、计算复杂的问题,本文进行了基于光滑粒子流体动力学算法(SPH)与移动立方体算法(MC)相结合的海浪建模仿真研究。通过基于空间网格的粒子分配,建立了粒子群单向列表存储结构,在海浪粒子物理量计算时,实现了其光滑核半径内粒子群的快速检索,并基于拉格朗日流体控制方程,进行了海浪粒子受力分析及状态计算;在模拟海浪与环境障碍物碰撞时,将碰撞问题简化为粒子在一定时间段内所经过的路径与障碍物表面三角面片是否相交来进行判定,并假设粒子为理想刚体,采用改进的欧拉方法实现了粒子新位置的动态计算;为增强海浪流体模拟的真实感,在移动立方体节点密度动态计算基础上,依据确定的海浪表面密度阈值,耦合MC算法进行了海浪表面的动态提取,从而实现了海浪三维表面建模与动态演变仿真。通过模拟验证了该算法的时效性与可行性,可为海洋环境信息三维可视化提供一定的参考。

关键词: 光滑粒子流体动力学, 移动立方体算法, 海浪仿真, 粒子系统, 网格分析

Abstract:

Traditional algorithms for modeling sea waves have some problems such as poor ocean surface realistic simulation and complicated calculation procedures. In order to solve these problems, this study presented a new sea wave simulation method which combines the Smoothed Particle Hydrodynamics (SPH) algorithm with the Marching Cubes (MC) algorithm. Based on space lattices, particles were allotted into different cubes and we established one way list structure for particle swarms storing and realized fast searching for particles within the smooth core radius in the calculation procedures of wave particle physics such as velocity, accelerator, position and so on. The force of the wave particle is generally composed of three parts: gravity, pressure gradient force and viscous force. Pressure gradient force is generated by the pressure difference between the fluid. Viscous force is caused by the velocity difference between the particles. According to this analysis of particle force, this study gave the Lagrange fluid control equation used for the accelerator calculation of ocean particles. In order to simulate the collision between particles and coastal barriers, we modeled the barrier surface as TIN (Triangular Irregular Network) and simplified the collision detection as whether the particle path passed through the triangle interface within a certain time. Assuming the particle as ideal rigid body, this study introduced an acceleration variation coefficient to calculate the particle's velocity after bouncing and improved the Euler equation by using the average velocity to calculate the particle's new position. In order to enhance the realistic simulation of the ocean wave fluid at the particle allotting time in the machine cube, this study calculated the density for each cube node dynamically. Through setting the threshold of sea surface density, we also extracted the wave surface dynamically by using linear interpolation method to generate triangular irregular network and realized the ocean waves 3D surface modeling and dynamic simulation. Through simulating, it verified the effectiveness and feasibility of this algorithm and could provide certain reference for ocean environmental modeling and virtual visualization.

Key words: smoothed particle hydrodynamics, marching cubes, sea wave simulation, particle system, cube analysis