反应运移模拟在实际应用中的主要制约因素是其计算量巨大,对模拟程序并行化可以拓展反应运移模拟的应用范围。在阐述反应运移模拟耦合过程的基础上,介绍了TOUGHREACT基于MPI的并行实现方法。以ECO2N模块为例,通过分析程序的流程图、加速比和并行效率,探讨TOUGHREACT并行程序的计算性能,并通过加密网格的方式对其加速效果进行验证。结果表明:基于MPI的TOUGHREACT并行程序采用METIS区域分解方法和AZTEC并行迭代解法器库,有效地实现了对TOUGHREACT的并行加速;在计算集群上调用2-128个处理器时,可以达到2.00-68.09倍的相对加速,显著提高了程序的计算效率;网格的剖分精度越高,该程序的并行效果就越好,表明该程序对复杂问题的并行加速效果更优。
Subsurface reactive transport modeling is an important tool for solving problems of geoscience and environmental science with complex physical and chemical processes. TOUGHREACT is a simulator for nonisothermal multiphase reactive geochemical transport in geologic media. This simulator requires a large computational time because of the mathematical complexity of reactive transport modeling. By using the parallel computing technique,the computational efficiency of TOUGHREACT can be improved significantly.To get more details about the implementation performance of TOUGHREACT and explore subroutines which can be parallelized,the flowchart of this code is drawn by using the performance analysis tool GPROF. Based on the ECO2 N module,we build a 2-D radial model of CO2-water-rock reaction in a carbon sequestration sand layer to evaluate the performance of the TOUGHREACT parallel version. Another two models with different grid subdivision precisions are built to verify the efficiency of the parallel code. The results indicate that the TOUGHREACT parallel version,by using MPI,METIS domain decomposition software package and AZTEC linear solver package,achieves a great relative parallel speedup for 2. 00 to 68. 09 by using 2 to 128 CPUs on cluster. The conclusion can be drawn that better performance can be achieved as the grid resolution increases.