锚链提升器水平液压管内气泡流型及其对边界层速度梯度影响分析

为有效提取气泡对管路边界层的扰动参数,达到提前预测和判断空气对液压管路污染的目的,基于管路流动边界层理论和气液两相流动理论,通过Fluent仿真平台建立气液管路模型,计算得到气泡流型及其对边界层速度梯度的影响规律。通过实验验证了仿真模型中气泡流型变化的一致性,并提出了一种液压系统空气污染诊断的新方法。计算结果表明,该方法能通过提取边界层微观变化规律来监测液压系统宏观空气污染故障;但是,当气泡直径小于0.01 mm时,则面临监测不到边界层速度梯度变化的情况。

Analysis of Bubble Flow Pattern in Horizontal Hydraulic Pipe of Anchor Chain Hoist and Its Influence on Velocity Gradient of Boundary Layer

To effectively extract the parameters of effects of bubbles on the boundary layer of pipelines, a pipeline flow model based on the boundary layer theory of pipeline flow and gas-liquid two-phase flow law is established by using the software Fluent. Via the developed model, the influence of bubble flow in gas-liquid two-phase flow on the velocity gradient of boundary layer is studied, and the purpose of predicting and judging the air pollution to the hydraulic pipeline in advance is achieved. The accuracy of the simulation model and the bubble flow pattern change are verified by experiments. Therefore, a new method for early diagnosis of air pollution in hydraulic system is proposed in this study. The simulation results show that the method can detect the air pollution fault of hydraulic system by extracting the micro variation of boundary layer. Notably, the velocity gradient of the boundary layer cannot be monitored when the bubble diameter is less than 0.01 mm.