涡轮盘轮缘封严结构参数对封严效率影响的实验研究

Influence of Different Structural Parameters on Sealing Efficiency of Turbine Disc Rim

关键词:  转静系  封严环  结构参数  封严效率

Key words:  Rotator-stator system  Rim seal  Structural parameters  Sealing efficiency

摘要:

在航空发动机涡轮部件中，封严环的设计对涡轮盘腔的冷却封严有着至关重要的作用。使用CO₂浓度测量法针对静盘双齿动盘单齿封严环的结构参数(齿高和齿间距)变化对封严效率的影响进行了实验研究，目的在于获得封严结构的封严效率和最小封严流量的变化规律。实验在主流雷诺数[Rew]=4.39×105，旋转雷诺数7.51×105<[Re?]<1.30×106的范围内，测量了不同封严流量下的封严效率，以及不同结构参数下各工况的最小封严流量。结果表明:封严效率随封严流量和旋转雷诺数的增加而增加；最小封严流量随着齿间距的增大和齿高的减小而增大，[Gc]平均每增加7.5×10-4，所需的最小封严流量会增加8.0%，[Gov]平均每增加1.12×10-3，可使最小封严流量减少4.7%，同时旋转雷诺数的变化对变齿间距下的最小封严流量有明显效果，而在变齿高情况下则没有影响。

Abstract:

In aero-engine turbine components， the design of the sealing ring is very important for the cooling and sealing of the turbine disc. Effects of different structural parameters (seal clearance and axial overlap of radial-clearance seal) of the rim seal which has two seal teeth on the stator and one on the rotor on sealing efficiency were experimentally studied by measuring CO₂ concentration， in order to obtain the change rule of the sealing efficiency and the minimum flow rate of sealing air of the different sealing structure. Experiment was conducted under the condition that annulus Reynolds number ([Rew]) was set at 4.39×105 while the rotating Reynolds number ([Re?]) changed from 7.51×105 to 1.30×106 in order to investigate the sealing efficiency under different values of the sealing air and the minimum flow rate of sealing air with different structural parameters. The results indicate that， the sealing efficiency increases with the increase of the sealing air and the rotating Reynolds number， the minimum flow rate of sealing air increases as the seal clearance increases and the axial overlap of radial-clearance seal decreases. If the[Gc]increases 7.5×10-4， the minimum flow rate of sealing air that is necessary will increase by an average of 8%. While if the[Gov]increases 1.12×10-3， the minimum flow rate of sealing air will decrease by 4.7%. At the same time， the change of rotational Reynolds number has obvious effect on the minimum seal flow， when the seal clearance is changed. However it is different when the axial overlap of radial-clearance seal is changed.