机载中空纤维膜组件壳程气体流动数值模拟

机载惰化用中空纤维膜组件具有分离效率高、安全稳定、结构紧凑等优点，是目前较为经济高效的飞机燃油箱惰化设备。采用计算流体力学(CFD)方法对某中空纤维膜组件壳程气体流动进行数值模拟，通过更改膜丝束间距、膜丝束入口速度、膜丝束流量、膜丝束排布方式及飞行高度，得到了不同工况下的组件轴向各截面的气体流动分布，并提出无量纲参数截面平均速度比来描述气体流动分布规律。仿真结果表明:在保持入口气体流动速度一定时，平均速度比值随着膜丝束间距的减小先减小后增大，在膜丝束间距为1.5倍膜丝半径时达到最小值, 在保持入口流量一定时，壳程气体流动有着相同的规律；在保持膜丝束填充数量不变时，均匀排布比不均匀排布的平均速度比值更小；保持膜丝束间距不变时，入口速度对平均速度比值影响不大；飞行高度对组件壳程气体分布的影响作用主要体现在膜组件内壁处。 

Numerical simulation of shell-side gas flow of airborne hollow fiber membrane module

Hollow fiber membrane module used for airborne inerting has the advantages of high separation efficiency, security, stability and compact structure. It is a relatively economic and efficient equipment of aircraft fuel tank inerting. The computational fluid dynamics (CFD) method is used to simulation shell-side gas flow of hollow fiber membrane module. By changing the gap, entrance velocity, rate of flow, arrangement mode of membrane tow and flight height, the gas flow distribution of the axial sections of component under different working conditions is obtained. The dimensionless parameter sectional average velocity ratio is put forward to describe gas flow distribution rule. The simulation results show that sectional average velocity ratio decreases at first and then increases with the decrease of the gap when entrance velocity is constant, and reaches the minimum when the gap is 1.5 times of the radius of membrane tow, and shell-side gas flow has the same rule with constant rate of flow. When the gap is constant, sectional average velocity ratio of uniform distribution is lower than that of non-uniform distribution. With constant the gap, entrance velocity has little effect on sectional average velocity ratio. The effect of flight height on the shell-side gas flow of the module is mainly reflected from the inner wall of the membrane module.