一种模拟气液两相流的格子波尔兹曼改进模型  

A NOVEL LATTICE BOLTZMANN MODEL SIMULATING GAS-LIQUID TWO-PHASE FLOW

作　　者：史冬岩[1] 王志凯[1] 张阿漫[2] 

机构地区：[1]哈尔滨工程大学机电工程学院,哈尔滨150001 [2]哈尔滨工程大学船舶工程学院,哈尔滨150001

出　　处：《力学学报》2014年第2期224-233,共10页Chinese Journal of Theoretical and Applied Mechanics

基　　金：国家自然科学基金(50939002);优秀青年科学基金(51222904)资助项目~~

摘　　要：基于格子波尔兹曼自由能模型,提出了一种模拟黏性流场中大密度比气液两相流的改进模型.为了提高模型的精度,在原始模型的基础上计入了邻近点间粒子数密度的传递速率控制,考虑了碰撞项的差分松弛;为了避免两相间大密度比造成的数值不稳定问题,分别采用六点和九点差分格式求解和2.同时,与传统格子波尔兹曼方法不同,实现了由单步碰撞操作到两步操作的转化.通过对无重力场中气泡的模拟及与已有模型的计算结果的对比分析,表明该模型具有更高的数值精度.成功模拟了重力作用下,单个上浮气泡的形变和尾涡形成过程,以及水平和竖直方向上两个气泡的相互作用过程,并验证了其质量守恒和体积不可压缩性.Based on the lattice Boltzmann free-energy model, a novel model is developed to simulate the gas-liquid two-phase flow with great density ratio in the viscous field. To improve the accuracy, the transfer rate control of the particle number density between two adjacent points is added to the original model, and the differential relaxation of the collision term is considered. Also, to avoid the numerical instability problems caused by the large density ratio, the six point and nine point differential schemes are used to solve △ and △2, respectively. Different from the traditional LBM implementation process, the single-step operation is divided into two steps in the paper. Unconsidering the gravity, the bubble motion is simulated and the results are compared with those from the exited models. It shows that the newly developed model has higher accuracy and numerical stability. Also, the deformation and the vortex formation of a rising bubble under gravity and the interaction of two bubbles in the horizontal and vertical directions are simulated. In the process, the mass conservation and the volume incompressibility are verified.

关 键 词：格子波尔兹曼方法 气泡 两相流 黏性流场 

分 类 号：O359[理学—流体力学]