Study on Pressure Fluctuation of Coarse Slurry Flow in Pipes

（1）目的：本研究旨在通过对水平管内固液两相流压力脉动特性的研究，特别是对粗颗粒浓度、粒径和细颗粒添加剂浓度对入口和充分发展区压力脉动的影响进行研究，为粗颗粒浆体管道系统的设计提供有意义的成果。管道中颗粒行为与压力脉动的关系以及MEP在管道固液两相流压力脉动中的应用。（2）方法：为实现这一目标，本文对水平管道中粗颗粒浆体流动的压力脉动进行了测量，对流动中固液两相的速度及其脉动剖面进行了测量，并对细颗粒添加剂对压力脉动的影响进行了实验研究。a）充分发展区的压力脉动随固体浓度的增加而增大，颗粒直径小于2mm时，压力脉动随固体浓度的增加而增大，超过2mm时，压力脉动随固体浓度的增加而增大，颗粒直径小于2mm时，压力脉动随固体浓度的增加而增大。压力波动不受颗粒直径的影响，几乎为恒定值。B）与固体进料器的距离影响压力波动。但当管道内形成沙丘时，波动水平沿沿着几乎相同，c）在具有存款床的流动和具有移动床的流动的过渡区域中观察到由于固体运动引起的最大压力波动，因为流动行为影响压力波动。d）观察到细颗粒添加剂减小压力波动。将MEP应用于管道固液两相流压力脉动概率密度函数的估算，表明四阶矩MEP分布函数适用于管道固液两相流压力脉动概率密度函数。

(1)OBJECTIVE: This research objective is to get some siginificant fruits for designing coarse slurry pipeline system from the study on the characteristics of pressure fluctuations in solid-liquid flow in horizontal pipes, especially, on the effects of coarse solid concentration, particle diameter and fine particle additive concentration on the pressure fluctuations in entrance and fully developed region, the relation between the particle behavior in pipes and the pressure fluctuations and on application of MEP to the pressure fluctuations in solid-liquid flow in pipes.(2)APPROCH: In order to achieve the objective, the measurement of pressure fluctuations in coarse slurry flow in horizontal pipes, the measurement of velocity and its fluctuation profile of solid and liquid in the flow and an experimental study on the effect of fine particle additive on the pressure fluctuations are projected.RESULTS: a) The pressure fluctuation in fully developed region increases with an increase in the solid concentration and particle diameter under 2 mm. Once it exceeds 2 mm, the pressure fluctuation is not affected by the particle diameter and nearly shows the constant values.b) The distance from the solid feeder affects the pressure fluctuation. However, when dunes are formed in the pipes, the fluctuation level is ovserved to be almost the same along, the pipes.c) The maximum pressure fluctuations due to the solid motion are observed in the transition region from the flow with a deposit bed and the one with a moving bed since the flow behavior effects the pressure fluctuations.d) The fine particle additive is observed to reduce the pressure fluctuation.e) It became clear from the application of MEP to estimattion of the probability density function of pressure fluctuation in solid-liquid flow in pipes that four moments MEP distribution function is suitable for the probability density function.