基于逆向射流抑制封严篦齿泄漏流动的数值及实验研究

针对一直通型篦齿通道进行了二维数值模拟，建立了9种封严结构模型，重点研究了位置和角度变化时逆向射流对篦齿内部流场的影响，探讨了不同模型下篦齿前后压比与泄漏系数的关系，发现各工况下的逆向射流在一定程度上都能够增强篦齿的封严效果，并且射流角度越小，密封性能越佳，射流位置在第一节齿腔中间时，抑制泄漏的效果最佳，当射流角为45°，射流位置在第一齿腔中间时，泄漏系数相对不带逆向射流时能够降低11.5%。在此基础上，进行了带逆向射流的二维直通型封严篦齿实验，在不同的压比下，用PIV分别测量了3种射流角度和3种射流位置下的篦齿通道内部流场，实验结果与数值计算变化规律一致。 

Numerical and experimental study based on reverse jet to suppress leakage flow in the labyrinth seal

Two-dimensional numerical simulations were performed for a straight labyrinth seal passage, nine kinds of sealing structure model were established, the effects of reverse jets at different positions and angles on the internal flow field of the labyrinth were studied emphatically, and the relationship between the front and back pressure ratio of the labyrinth and the leakage coefficient under different models was discussed. The results show that all different jet positions and angles can enhance the seal effect of labyrinth seal, the smaller jet angle, means the better sealing effect, when the jet position was in the middle of the first section of the tooth cavity, the leakage effect was the best. When the jet angle θ was 45 ° and the jet position was in the middle of the first tooth cavity, the leakage coefficient can be reduced by 11.5% corresponding to the case without reverse jets. On the basis of numerical simulation, a two-dimensional straight labyrinth seal experiment with reverse jet was proceeded, using PIV to obtain the flow field with reverser jet under three jet angles and three jet positions, the experimental results were consistent with the calculated variation law.