管式减涡器入口局部压降和流阻特性

使用CFD仿真分析的方法,研究了带有导流管式减涡器的盘腔内空气流动和损失特性,重点阐明了导流管的减阻机理,特别是不同结构下管口处的流动与局部损失特性,并提出了一个数学模型来预测导流管盘腔内的压力。研究表明:管口处的流动及损失特性与管口之前的流动状态密切相关,且管口处发生的静压损失不容忽视,约占具整个盘腔损失的11%;合适的导流管长度可以有效的改善管口处的损失,在当前研究工况下具有最佳导流管长度的结构可以降低约25%的管入口处局部压降,约10%的整体静压降;建立了可以精确计算盘腔内压力分布的数学模型,模型计算结果与CFD结果相比平均误差约为53%。 

Local pressure drop and flow resistance characteristic at entrance of tubed vortex reducer

The flow structure and flow loss characteristic in a rotating cavity with tubed vortex reducer were studied numerically. The study focused on the mechanism of the tubed vortex reducer, especially the local loss characteristic at the tube entrance under different geometric parameters of the tube. Based on these studies, a mathematical model for predicting the pressure drop in a tubed cavity was established. It was found that the local loss characteristics at the tube entrance were related to the flow state before the entrance, and the incident angle can describe this flow state well. The static pressure loss at the tube entrance cannot be ignored, accounting for about 11% of the total static pressure drop in the rotating cavity. Furthermore, the tube with a moderate-length can restrict the rotation of the air and reduce the pressure drop in the rotating cavity more effectively. Under the research conditions, the tubed vortex reducer with the optimal tube length can reduce the local pressure drop at the tube entrance by about 25% and the overall static pressure drop in the cavity by about 10%. This also showed that, the mathematical model can provide accurate results of the static pressure distribution in the tubed vortex reducer. The average error was about 53% between the CFD results and the mathematical model results.