气—幂律两相流体流经截面突缩管的数值模拟

Numerical simulation on two-phase flow of air and power-law liquid through suddenly shrunken channels

为揭示空气—幂律流体流经截面突变时的两相流动规律,尤其是两相参数沿流向及管截面分布及压降的变化规律,根据气液两相流理论,并考虑幂律流体的本构方程,建立了空气—幂律流体两相流动数学模型。在此基础上,采用商业软件Fluent对空气—幂律两相混合物流经截面突缩管道的流动特性进行了数值模拟,获得了两相参数沿轴向及截面方向的分布规律。研究表明:气相、液相速度及压降随着输入含气量的增大而增大;两相参数在截面突变附近有急剧的改变,但其突变位置却有所不同;另外,两相参数的截面分布沿流程也有所不同。这些研究结果对相关系统的设计提供了理论依据。

A mathematical model of two-phase air and power-law flow is developed on the basis of the two-phase flow theory of gas and liquid and the constitutive equation of power-law fluid. The flow characteristics of two-phase mixtures of air and power-law fluid through a suddenly shrunken channel are numerically simulated by using commercial software named Fluent. Then the distribution law of two-phase parameters along axial and sectional directions is obtained. Research results show that the higher the gas velocity, liquid velocity, and pressure drop are, the more the input gas content increases. What's more, the two-phase parameters change abruptly nearby the suddenly shrunken section, yet the mutation positions are different. In addition, the sectional distribution of the two-phase parameters is also different along axial direction. All the research results provide a theoretical basis for the design of relevant systems.