高转速下台阶篦齿流动特性的实验与计算

Experimental and Numerical Investigations on Flow Characteristics of Stepped Labyrinth Seal at High Rotational Speed

对航空发动机压气机级间台阶篦齿封严进行了实验与计算研究。在不同压比(1.05~1.3)下,研究了转速(1.5~7.2kr/min)对篦齿的工作间隙变化、泄漏特性、温升特性和旋流特性的影响,并选取典型实验工况进行了数值模拟。研究表明实验结果与数值计算结果符合良好。随转速的增大,工作间隙减小,泄漏流量降低,两者最大降幅在40%左右;较小压比时流量系数微弱降低,较大压比时流量系数微弱增大。系统风阻温升随转速的增大而增大,且转速越大温升越快,最大温升为36K。另外,出口旋转盘腔同一径向位置的旋转比随转速的增大而增大,最大可达0.398;同一转速下,随出口旋转盘腔径向位置的增大,旋转比降低。

Experimental and numerical investigations on stepped labyrinth seal in the aero-engine compres- sor stator well were carried out. The effects of rotational speed （1.5 - 7.2kr/min） on the variation of working tip clearance, sealing characteristics, windage heating characteristics and swirl characteristics were studied at dif- ferent pressure ratios （ 1.05 - 1.3）. In addition, numerical simulations were carried out under the typical experi- mental conditions. The results show that the numerical calculations agree well with the experimental data. With the increasing of rotational speed, the working tip clearance and the leakage mass flow decrease, and the largest reduction reaches about 40%. For low pressure ratios, the discharge coefficient decreases slightly, while the dis- charge coefficient increases slightly for high pressure ratios. Increasing the rotational speed leads to an increase in the system windage heating. The higher the rotational speed is, the faster the temperature rises, and the high- est temperature rise reaches around 36K. Besides, by increasing the rotational speed, the swirl ratio at a specif- ic radial location of the outlet disc cavity increases, which can be as high as 0.398. However, the swirl ratio shows a decrease with radius increasing in the outlet cavity at the same rotational speed.