非线性振动下水平通道内气液两相流动研究

Study on Gas-liquid Two-phase Flow in Horizontal Channel under Nonlinear Oscillation

在地震等行为产生的非线性振动下,两相流体会影响回路传热并对装置结构进行冲击,因此对气液界面行为的把握对核安全具有十分重要的意义。本文通过将振动装置与两相流实验回路相结合的方法,对非线性振动下水平通道内气液两相流问题进行了实验研究。基于FLUENT平台,结合动网格模型及UDF编程手段建立了数学模型,并对数学模型进行验证。研究结果表明:模拟结果与实验结果具有很好的一致性;振动工况下气液两相流动形式不同于稳态工况,会出现更复杂的气液界面,主要流型有泡状流、弹状流、搅拌流、波状流及环状流;瞬时摩擦压降的波动幅度随振动幅度和频率的增大而增大,且与振动幅度相比,振动频率对其影响更大。

Under nonlinear oscillation caused by seism,two-phase flow will affect loop heat transfer and impact reactor structure,so it is meaningful to study the gas-liquid interface behavior under seismic nonlinear oscillation.According to the method of combining vibration apparatus with two-phase flow experiment loop,the experimental study on gas-liquid two-phase flow in horizontal channel under nonlinear oscillation was conducted.At the same time,based on FLUENT platform,combined with dynamic mesh technique and UDF programming method,the mathematical model was established and verified.The results show that the simulation and experiment results are in reasonable agreement.The flow patterns of gas-liquid two-phase flow under nonlinear oscillation are different from those under steady condition,resulting in more complex gas-liquid interface,and main flow patterns are bead flow,fluctuant slug flow,boiling wave flow,wave flow and annular flow.As vibration intensifying,the magnitude of frictional pressure drop increases,showing vibration frequency has a stronger effect on fluctuation than vibration amplitude.