直通型篦齿泄漏的特性试验

对广泛应用于航空发动机的直通型篦齿进行试验,测量了不同结构组合,不同工况参数下直通型篦齿的流量和压力,计算得出相应的换算流量系数,分析了倾斜角度、间隙以及转速对换算流量系数的影响,并获得经验关联式.研究表明:当进、出口气流压比较小时,篦齿换算流量系数随压比增加较快,然后增加缓慢,并渐趋于一定值;相同压比下,篦齿向来流方向倾斜角度和间隙宽度减小,换算流量系数均减小,倾斜角度存在最佳值,应在45°~60°;转速的影响过程较为复杂,在本试验范围内换算流量系数随其增加而减小. 

Experiment on discharge characteristics of straight-through labyrinth

Experimental investigation was conducted on the discharge characteristics of the straight-through labyrinth,which was applied widely in aero-engines,under different configurations and operating parameters.Influences on the nominal discharge coefficients of the inclination angle,the clearance of the labyrinth pins and the revolving speed of the shaft were considered.Discharge flow rate and pressures at the entrance and the exit of the labyrinth were measured,and then nominal discharge coefficients and a correction equation were acquired.Moreover,comparisons of experiment data with data calculated from the classical correction equation were done.The results show that nominal discharge coefficients increase with the rising ratio of the inlet total pressure and the outlet pressure,and then tend to a certain constant for each configuration at each operating point.However,they decrease with the decreasing inclination angel and clearance of the through labyrinth in this study.Also the optimum value of inclination angel is in a range of 45°~60°.For the shaft revolving speed of the labyrinth disc,it works complicatedly,and nominal discharge coefficients decrease with its increase clearly.