湍流对气固两相流动中颗粒受力的影响  

Effect of turbulence on the drag in a gas-particle two-phase flow

作　　者：由长福[1] 祁海鹰[1] 徐旭常[1] 

机构地区：[1]清华大学热能工程系,煤的清洁燃烧技术国家重点实验室,北京100084

出　　处：《清华大学学报（自然科学版）》2002年第10期1357-1360,共4页Journal of Tsinghua University(Science and Technology)

基　　金：国家"九七三"重点基础研究专项经费资助项目( G 19990 2 2 2 )

摘　　要：采用数值计算方法研究了流经静止球形颗粒的湍流流动。考察了不同湍流模型 (标准 k-ε模型、RNG k-ε模型和 Realizable k-ε模型 )对后台阶流动的计算结果的准确性 ,从中选取表现比较优越的 RNG k-ε模型对颗粒附近的湍流流动进行详尽的数值模拟。计算中湍流度取为 10 %～ 80 %之间 ,湍流尺度为 10 -5～ 4m。发现湍流尺度的变化对曳力系数的影响比较小 ,只是在小尺度条件下存在一定影响 ;而湍流度对颗粒曳力系数产生较大的增强作用 ,尤其在小颗粒Rep 条件下。得出的结论与以往文献不同 。The flow over a stationary spherical particle was analyzed numerically to analyze the effect of the turbulent parameters (turbulence intensity and turbulence length scale) on the drag force. Several turbulence models were compared by using the models to analyze turbulent flow over a backward facing step. The RNG k ε model produced the best results so it was used to simulate the turbulent flow over the sphere. The turbulence intensity was varied from 10% to 80% and the turbulence length scale was varied from 10 μm to 4 m. The results showed that the turbulence length scale had a small effect, except at very small length scales less than the particle diameter. The turbulence intensity significantly increased the drag especially at low particle Reynolds numbers, which differed from the result of previous publications.

关 键 词：颗粒受力 湍流 曳力 数值模拟 气固两相流动 数值计算 流体速度 

分 类 号：O357.5[理学—流体力学] O359[理学—力学]