迷宫密封的湍流增阻

迷宫密封是依靠节流间隙中的节流过程和迷宫空腔内的动能耗散过程来实现密封的,这两个流体流动过程从本质上规定了迷宫密封的密封性能。通过密封内部流动本质的研究,可以利用湍流流动的一些规律和特点,发挥密封内部湍流的增阻作用,提高密封性能。通过对一种锯齿形迷宫密封的数值和试验研究,揭示了湍流惯性偏转和射流收缩在湍流增阻中的作用。利用这些湍流增阻的原理,可以突破节流间隙的微小尺寸限制,实现较大间隙下的良好密封,这不仅会给迷宫密封的制造、安装及运行等带来很大的方便,而且可以为发展新的迷宫密封理论奠定理论基础。

RESISTANCE ENHANCEMENT OF LABYRINTH SEAL BY TURBULENCE

The property of labyrinth seal relies on the throt- tling process in clearance and the dynamic dissipating process in cavity these two procedures play decisive roles in essential to the sealing property of the labyrinth. Study on the flow field in labyrinth seal is helpful for us to make use of some charac- ters of turbulence in improving the sealing property Model experiment and numrical simulation are adopted to study the seal mechanism of a crenellated radial labyrinth. It is shown that now deflection in throttle clearance can effectively de- crease the actual flow area in the clearance and improve the seal property. Thus the flow deflection in throttle clearance can be utilized to replace the small clearance, and a better seal property can be achieved under condition of wide clearance. This is of great importance to the design, production and operation of labyrinth, and lays a foundation for the invention of newly con- structed labyrinth seal.