篦齿封严尺寸缩放与气流温度变化对流动与传热影响试验研究

Experimental Investigation of Scaling and Temperature Effects on Flowing and Heat Transfer Characteristics in Labyrinth Seals

利用矩形、梯形齿篦齿封严直通齿模型,将真实尺寸篦齿封严等比例放大,对真实尺寸模型与放大模型的流动与换热特征进行了试验研究与对比分析,并研究了气流温度变化对流量系数的影响。研究发现,放大模型与真实尺寸模型的流量系数与努赛尔数均随雷诺数增大而增大,在雷诺数相同时两者的流量系数与努赛尔数基本相等,最大差值分别为5.3%和9.7%。放大模型较好地保持了真实尺寸篦齿封严狭小空间流动与换热特征。研究还发现,在加热条件下,流量系数相比冷态条件下有所减小。

Based on the real labyrinth seals, the rectangular and trapezium scaling models were designed by exemplifying the original ones by times. The flow and heat transfer characteristics of the scaling and original seals were experimentally investigated and compared, in the same time, the effect of temperature on flow effi-ciency was investigated. The results showed,the flowing efficiency and Nusselt number of the original and scal-ing models all increase with Renaults number,and have the similar values,the largest difference of flowing and heat transfer efficiency between the scaling and original models are 5.3%and 9.7%,respectively. It can be con-cluded that the scaling models keep the same flow and heat transfer characteristics formed in small gaps of the original seals. It was also found that flowing efficiency decreased with gas temperature rising.