二维复杂域PEBI网格细化生成算法

2D PEBI gird generation for complex domain by refinement algorithm

本文给出了二维PEBI网格有关概念,对其已有生成方法进行了系统的分析.针对这些方法的不足,提出生成二维PEBI网格的优化检测带细分算法,先根据限定条件设置初始等腰梯形检测带,然后设计算法来细分检测带,以实现PEBI网格的快速生成.文中还进行了算法收敛性分析和时间复杂度分析.最后给出算法实例,验证了该算法的正确性和有效性.与已有PEBI网格生成算法相比,在限定线段间存在较小夹角时,本算法能有效消除这部分畸形网格单元,提高网格单元质量,扩大算法适应性;同时减少限定线段区域外的PEBI网格单元数目,提高算法效率.本算法在油藏数值模拟等领域有很好的应用前景.

Some terms related to 2-D PEBI grid are put forward,and then the current PEBI grid generation techniques are systematically analyzed and studied.Aiming at solving these shortages,an optimized examining strip subdivision algorithm for 2-D PEBI grid generation is presented.First,the initial isosceles trapezoid examining strip sets are settled according to the restriction condition,then an algorithm is designed to subdivide the examining strip to realize the speedy generation of PEBI grid.The analysis of the convergence and the time-complexity of this algorithm are also presented.An implementation example is given finally to indicate the validity of the algorithm.Supposing small angles are existed between constrained line segments,compared with the existing PEBI grid generating algorithms,this algorithm can eliminate the abnormal grid cells effectively and improve the quality of generated cells and the adaptability of the algorithm.Moreover,the number of PEBI cells outside the constrained region can be reduced and the algorithm efficiency is improved.