U型节流槽等压差活门内流场特性

以某U型节流槽等压差活门为研究对象,开展了内流场性能数值模拟研究.基于三维建模造型技术对所设计的压差活门进行初步建模,然后采用周期性网格网格单元划分等压差活门的结构化网格;进而通过CFD数值模拟进行了内流场仿真分析,并对不同出口节流开度的等压 差活门模型进行了对比研究.内流场状态表明:U型节流槽等压差活门不同流量以及不同出口节流开度下在节流口处由于面积突变,压力梯度变化较大,等压差活门的压降主要集中在此处,且均存在一定范围低速团与二次旋涡流等.仿真结果预测的外特性性能表明:等压差活门的压差在不同流量工况下和相同流量的不同出口节流开度下,压差维持在0.9MPa左右,符合设计要求.且不同出口节流开度下压差变化趋势相似,出口节流开度越大,压差越大,小流量下相应更快. 

Flow field characteristics of the U-shaped throttling constant differential pressure valve

As the research object of a U-shaped throttling constant differential pressure valve, numerical simulation study was carried out based on three-dimensional modeling technology, the preliminary model of pressure valve was designed, then structured grid was divided by using periodic mesh. Finally the inner-flow performance was simulated and the flow field of the pressure valve was analysed, and then the performances between different pressure valve''s output opening were compared. The inner flow state indicates: under different flux and opening, the pressure gradient is large because of area change, pressure drop is mainly concentrated around the break zone, and some low-speed ranges and secondary vortex flows move around. The predicted performance of the external characteristics shows that: for both different flow rate and different opening degrees at the same flow conditions, pressure difference is maintained at around 0.9MPa, meeting the design requirements. And pressure change has a similar trend at different degrees of opening, the greater opening means the larger pressure, and low flow is accordingly faster.