CPU-GPU异构并行计算在数字岩心线弹性静力学有限元模拟中的应用

Application of CPU-GPU heterogeneous parallelled computation in linear elastic statics finite element simulation on digital rock

线弹性静力学有限元模拟是计算数字岩心弹性模量的有效方法之一,已被用于研究数字岩心的弹性模量与其微观结构、物质组成之间的关系.若要形成解决实际问题的能力必须计算足够多的数字岩心样本,而有限元模拟的计算量较大,因此并行计算对于该方法的成功应用非常重要.本文将数字岩心线弹性静力学有限元模拟算法分解为在CPU和GPU上执行的两个部分,由CPU负责协调控制,GPU负责大规模数值计算,实现CPU-GPU异构并行计算,获得计算效率提升.采用该并行算法计算孔隙数字岩心、裂缝数字岩心和裂缝—孔隙数字岩心的弹性模量,得到的弹性模量—孔隙度关系符合一般的岩石物理规律.CPU-GPU异构并行的线弹性静力学有限元模拟能够迅速计算大量数字岩心的弹性模量,提供相当于物理实验的"观测数据",对岩石物理学研究具有重要的意义.

Linear elastic statics finite element simulation is one of the effective methodologies to calculate elastic moduli of digital rock. It has been applied to study relationships between elastic moduli,microstructure and material composition of digital rocks.Parallelled computation is important to linear elastic statics finite element simulation,because computation amount of finite element simulation is large and a certain amount of digital rocks needed to resolve real problems. The linear elastic statics finite element simulation is carried out by CPU-GPU heterogeneous parallelled computation. One large part of code is executed on GPU and the other part of code is executed on CPU. Logical controlling code is executed on CPU,and the most part of numerical computation is on GPU. The computational efficiency increases compared to serial computation. Effective elastic moduli of porous digitial rocks,cracked digital rocks and cracked porous digital rocks are calculated. Relationship between effective elastic moduli and porosity is consistent with normal rock physics law. With the CPUGPU heterogeneous parallelled computation we can calculate various macro elastic moduli of many digital rocks quickly, obtain ＂observation data ＂ which is equivalent to laboratory experiments.CPU-GPU heterogeneous parallelled computation makes a great signifance to rock physics research.