凸起数对各封严结构封严效率影响的实验

实验用二氧化碳体积分数测量法研究了凸起数目的变化对盘腔内各参数（静压、总压、封严效率）的影响，目的是获得不同封严结构的封严效率和最小封严流量随凸起数目的变化规律。实验在主流雷诺数和旋转雷诺数为一定范围内，测量了不同封严流量下的参数。结果表明:在实验工况范围内，凸起的数目变化对腔内的静压影响较小，靠近封严环的静压变化几乎可以忽略；而总压和封严效率都和凸起数目成正比，但不同封严结构的变化程度有所不同。从整体上看，径向封严结构效率的提升最明显，轴向封严和静盘双齿封严改善较小。平均每增加一个凸起，三种结构所需的最小封严流量分别可以减少0.96%、0.30%、0.28%。此外，安装了凸起后，旋转雷诺数对封严效率的影响也会更加明显。 

Experiment on the effect of protrusion amount on sealing efficiency of different rim seals

The effect of different protrusion amounts on various parameters (static pressure, total pressure, sealing efficiency) was experimentally studied by measuring carbon dioxide volume fraction, so as to obtain the change rule of the sealing efficiency and the minimum flow rate of sealing air of different sealing structures. In the experiment, the experimental parameters of different dimensionless sealing flow rates were measured under the condition that the annulus Reynolds number and the rotating Reynolds number changed within a certain range. The results show that the change of the protrusions amount has little effect on the static pressure in the cavity, and the static pressure change near the sealing ring is almost negligible. The total pressure and sealing efficiency will increase with the increasing protrusion amount. However, the degree of change in the different sealing structures is different. As a whole, the efficiency of radial rim seal is most obvious, and the improvement of the axial rim seal and double teeth rim seal is less. For each additional protrusion, the minimum sealing flow rate required for each of the three structures can be reduced by 0.96%, 0.30%, 0.28%, respectively. In addition, the rotating Reynolds number will have a more significant effect on the sealing efficiency after the protrusions are installed.