变直径串联喷嘴内流特性研究

喷嘴在分层注入过程中起到调节聚合物分子量和压力损失的作用,而多级喷嘴的结构,由于分子链的逐级剪切作用,可在保证注入粘度的同时,更大的减小压力的损失.在此基础上提出变直径多级喷嘴的几何结构,利用Fluent数值模拟软件,对单级喷嘴、等直径多级喷嘴进行数值模拟,分析不同结构喷嘴对三元复合溶液速度、压力、湍动能以及平均应变速率的影响,结果表明随着流量的增大,三种结构喷嘴的压力损失和平均应变速率均增大,合理的变直径串联喷嘴可以达到与等直径串联喷嘴相同的注入效果,同时尺寸较小,方便工程应用.

Study on Flow Characteristics of Variable Diameter Nozzles

The nozzle is used to adjust the molecular weight of the polymer and the pressure loss in the layered injection process,the structure of the multi-stage nozzle can reduce the pressure loss at the same time to ensure the injection viscosity due to the progressive shearing effect of molecular chains.On the basis of this,this paper presents the geometric structure of variable diameter nozzle,then the numerical simulation of single stage nozzle and equal diameter nozzle is carried out by using Fluent numerical simulation software.The different structure of nozzle on the velocity,pressure,turbulent kinetic energy and the average strain rate of ASP solution were analyzed,and the results showed that with the increase of flow rate,the pressure loss and average strain rate of these three kinds of nozzles increased.The reasonable variable diameter series nozzle can achieve the same injection effect as the equal diameter series nozzle,and the size is small,which is convenient for engineering application.