封严间隙对盘缘密封性能影响的数值研究

通过对真实工况下高压涡轮的盘缘封严进行三维数值模拟,研究了3种不同轴向间隙和径向间隙对封严效率和盘腔内流场变化特性的影响规律,结果表明:针对复合封严结构及研究参数范围,由于静盘封严环将盘腔划分为封严外容腔和封严内容腔,而封严外容腔可以有效地将主流燃气阻隔在内，因此封严内容腔具有较高的封严效率。当轴向间隙增大时,封严环轴向重合度会逐渐减小,同时冷气出流阻力降低,盘腔的封严效率因而提高。当轴向间隙一定径向间隙逐渐减小时,封严外容腔径向距离减小,此时盘腔低半径处封严效率升高。

Numerical investigation on influence of sealing clearance on sealing performance

A three-dimensional numerical simulation of the rim seal of a high-pressure turbine was carried out. To reveal the sealing efficiency and the flow field characteristics in the cavity,different parameters of axial and radial clearances were analyzed. Results showed that the sealing ring divided the disk cavity into an outer cavity and an inner cavity. The outer cavity could effectively resist the mainstream gas,therefore the inner cavity had a higher sealing efficiency. With the increase of axial clearance,the overlap length and the resistance of the coolant flow decreased,so the sealing efficiency of the disk cavity was improved. With a constant axial clearance,the radial distance of the outer cavity decreased as the radial distance decreased. The sealing efficiency at the lower radial region could be improved.