导流结构对脉管制冷机性能影响的研究

Influence of Flow Straightener on the Performance of a Pulse Tube Cryocooler

提出了一种用于脉管制冷机的导流方法:在射流正前方引入挡片,消除射流对导流丝网的冲击作用,减小丝网对气体进行导流所需的阻力和产生的流动损失,从而提高制冷机性能。通过CFD模拟对挡片的作用机理进行了研究,表明导流挡片可以有效抑制脉管中涡流的出现,减少冷热气流的混合。进一步的实验研究验证了导流结构的积极作用,为脉管制冷机导流结构的设计提供了一种新的参考方式。

A new flow straightener composed of a small round plate and a stack of screens was designed and tested to improve the performance of a U-shaped pulse tube cryocooler.The round plate was proposed to put in front of the jet flow to eliminate its inertance impact on the screens,which helped to decrease the resistance of the screens and flow losses in the process of straightening.A CFD simulation was carried out to study the working mechanism of the plate.It was shown that the small plate can help to inhibit the formation of the eddy current in the pulse tube so as to decrease the mixture of the cold and hot fluid in it.The experimental results further verified the positive effect of the plate.The new configuration of the straightener could be valuable for the future design of pulse tube cryocoolers.