摘要
基于相似准则和气体真实物性参数提出一种格子Boltzmann模型中选取无因次松弛时间的新方法,同时考虑边界努森层的影响对无因次松弛时间进行修正,结合壁面二阶滑移边界条件推导出相应组合反弹/镜面反射边界条件中的关键参数,从而建立了基于格子Boltzmann方法的适用于高温高压条件的非常规天然气微尺度流动模拟新模型。将甲烷气体在无限长微通道中的体积力驱动流动及长直微通道中受进出口压差驱动流动的模拟结果与文献中数值解及解析解进行对比,验证了模型的准确性,并对无因次松弛时间修正式进行优选。结果表明,新模型可以有效表征非常规天然气微尺度流动条件下的滑脱效应、压缩效应、气体稠密性及边界努森层影响;实现了对气体真实流动条件更加全面的表征,可作为微纳尺度非常规天然气流动模拟研究的基础模型。
A new method for selecting dimensionless relaxation time in the lattice Boltzmann model was proposed based on similarity criterion and gas true physical parameters.At the same time,the dimensionless relaxation time was modified by considering the influence of the boundary Knudsen layer.On this basis,the second-order slip boundary condition of the wall was considered,and the key parameters in the corresponding combined bounce-back/specular-reflection boundary condition were deduced to build a new model of unconventional gas microscale flow simulation based on the lattice Boltzmann method suitable for high temperatures and high pressures.The simulation results of methane gas flow driven by body force in infinite micro-channels and flow driven by inlet-outlet pressure differential in long straight channels were compared with the numerical and analytical solutions in the literature to verify the accuracy of the model,and the dimensionless relaxation time modification was formally optimized.The results show that the new model can effectively characterize the slippage effect,compression effect,gas density and the effect of boundary Knudsen layer in the micro-scale flow of unconventional natural gas.The new model can achieve a more comprehensive characterization of the real gas flow conditions and can be used as a basic model for the simulation of unconventional gas flow on the micro-nano scale.
作者
赵玉龙
刘香禺
张烈辉
单保超
ZHAO Yulong;LIU Xiangyu;ZHANG Liehui;SHAN Baochao(State Key Laboratory of Oil&Gas Reservoir Geology and Exploitation,Southwest Petroleum University,Chengdu 610500,China;State Key Laboratory of Coal Combustion,Huazhong University of Science and Technology,Wuhan 430074,China)
出处
《石油勘探与开发》
SCIE
EI
CAS
CSCD
北大核心
2021年第1期156-165,共10页
Petroleum Exploration and Development
基金
国家自然科学基金重点项目“致密气藏储层干化、提高气体渗流能力的基础研究”(51534006)
国家自然科学基金面上项目“耦合压裂缝网扩展机制的页岩气藏动态模拟研究”(51874251)。
