振动对水平管内液氢两相流影响的数值模拟

Numerical simulation of liquid hydrogen two-phase flow in horizontal vibrating tube

液氢加注过程中,管路的振动会影响液氢加注的安全性与效率。为了研究低温管路振动对液氢加注过程的影响,从而使得加注过程快速安全进行,建立了液氢管路的三维模型,采用流体体积函数(VOF)耦合水平集(Level-Set)方法,针对不同管路振动频率及振幅条件,模拟并分析了管内液氢两相流的流动及传热特性。研究结果表明,管路振动在频率和振幅较大时增强了液氢与管路之间的换热,使得管内气泡增多;管内的压降随着振幅频率的增加而增大,管路的振动破坏了管内液氢气液两相流的稳定边界,并且促进了气泡的分离与聚合,进而影响了低温输运管路的稳定性。通过数值模拟为液氢的加注提供了理论指导。

During the liquid hydrogen filling process,the vibration of pipeline will affect the safety and efficiency. In order to study the influence of cryogenic pipeline vibration on the liquid hydrogen filling process and make the filling process fast and safe,a three-dimensional model of liquid hydrogen flowing in a pipeline was established. In this paper,the volume of fluid function(VOF） coupled with Level-Set method was employed to simulate and analyze the heat transfer and flow characteristics of liquid-hydrogen two-phase flow in different circular tube vibration frequency and amplitude conditions. The results show that the vibration of the pipeline increases the heat transfer between the liquid hydrogen and the wall when the frequency and amplitude are relatively large and hence increases the bubbles in the pipeline. The pressure drop along the tube increases with the increase of the vibration amplitude and frequency. The vibration of the pipeline destroys the steady boundary of the liquid-vapor two-phase flow in the tube and promotes the separation and mergence of the bubbles,and thus affect the stability of the pipeline. The numerical simulation provides theoretical guidance for the filling process of liquid hydrogen.