直通篦齿蜂窝封严结构的风阻特性试验

试验研究了直通直齿和直通斜齿与蜂窝衬套和光滑衬套4种组合的三齿两腔封严结构的风阻特性,得到了风阻特性随转速、压比、衬套和齿形结构的变化规律.结果表明:4种组合封严结构在低转速时风阻生热基本都可以忽略,转速在3000r/min到6000r/min之间变化时风阻生热引起的流体总温升随转速增大;采用光滑衬套时,泄漏流体流至首级齿腔处的总温升占进出口总温升比例维持在45%以上,而蜂窝衬套对气流黏滞作用大,低压比时首级齿腔总温升占进出口总温升的比例仅有20%左右,继续增加压比,首级齿腔处的总温升比例由20%增加到50%左右后保持不变;相同衬套时,斜齿比直齿具有较长的齿表面曲线长度,从而具有较高的风阻生热. 

Experiment investigation of windage heating on straight-through labyrinth seals with honeycomb bush

Experiment investigation of windage heat on straight tooth and slant tooth of labyrinth seals composed of three teeth and two cavities with honeycomb bush and smooth bush had been made to study the effect of rotating speed and the pressure ratio of inlet to outlet and structure of tooth and bush.The results show that the total temperature of leakage fluid caused by windage heat may be neglected at low rotor speed and is increased with the increasing rotation speed between 3000r/min and 6000r/min.The total temperature ratio of first tooth to all teeth is more than 50% with smooth bush and is only 20% with honeycomb bush under low pressure ratio and enhanced to 50% with the increase of the pressure ratio.The straight tooth show increased windage heat when compared to slant tooth with the same bush due to the larger extension length of seal surface curve.