摘要
湍流在宏观上处于远程混沌无序状态 ,而在介微观上处于近程有序状态。从分析湍流场中局域中涡旋的串级结构出发 ,通过对N S方程的涡旋输运形式进行求解 ,导出一个具有分形意义的涡旋群运动表达式 ,并得到涡旋掠过颗粒表面花费的时间 ,然后同Higbie的传质渗透模型相联系 ,以涡旋的分布函数为权求其数学期望 ,得到搅拌湍流场中的传质系数表达式 ,结果与实验数据吻合较好。
The transfer phenomena of turbulence flow in an agitated tank were studied. Though turbulence is a sort of chaos or confusion in the long-run on the whole, there exist self-similar ordered structures in a local micro region, where cascade fluid phenomena can be depicted by using the form of vortex transport of N-S equation. According to the cluster breakdown process of eddy and the characteristics of turbulence, as well as the influence on each other between the solid and vortex, the distribution of eddies could be found, and the average contact time in which the fluid sweeps the surface of the solid could be obtained. Considering the combination of eddy breakdown with fractal dimension and Higbie's penetration theory, a new turbulence mass transfer model was established. As the result, a model was valid for fitting the transfer experiment data.
出处
《化工学报》
EI
CAS
CSCD
北大核心
2004年第1期25-31,共7页
CIESC Journal
基金
国家自然科学基金资助项目 (No .2 0 0 460 0 1)~~
关键词
传质
分形
湍流
搅拌槽
Fractals
Mathematical models
Navier Stokes equations
Turbulence
Turbulent flow
Vortex flow
