PCCSAP-3D程序压力场算法改进

Improvement on Algorithm for Pressure Equation in PCCSAP-3D

介绍大型先进压水堆安全壳专用分析程序PCCSAP-3D计算采用的方法,引入GMRES(Generalized MinimalRESidual)方法改进该程序的压力场算法.使用GMRES算法的实用变形,并采用合适的预处理技术,比较GMRES算法和ML-ADI算法在求解压力方程时的收敛速度.结果表明,利用压力矩阵结构化和稀疏性的特点,采用预处理GMRES算法能够更快速地求解压力方程.当压力矩阵规模变大时,GMRES算法相对于ML-ADI方法能够节省更多的时间.

An algorithm for pressure equation in a computational code PCCSAP-3D, which is dedicated to analyze transient process of PCCS （Passive Containment Cooling System） , is introduced. GMRES is introduced to accelerate calculation speed. Pre-conditioning of GMRES is applied. Convergence rates of GMRES and ML-ADI are compared. It shows that pre-eonditioned GMRES can be used to solve pressure equations more efficiently. Since pressure equation coefficient matrix is structural and sparse, pre-conditioned GMRES is more efficient than ML-ADI as pressure equation coefficient matrix is larger.