基于数值模拟的矩形凹槽对直通型篦齿封严特性影响研究

Investigation on Effects of Rectangular Groove on Leakage of Straight-Trough Labyrinth Seal Based on Numerical Simulation

关键词:  封严篦齿  凹槽  泄漏系数  封严效率  数值模拟

Key words:  Labyrinth seal  Groove  Leakage coefficient  Seal efficiency  Numerical simulation

摘要:

为了提升封严篦齿的封严性能,对在机匣上开设矩形凹槽的直通篦齿结构中的流动特征和封严性能进行了数值模拟,获得了凹槽篦齿的涡流结构、泄漏系数和封严效率,并与光滑篦齿的结果进行了对比。研究了凹槽尺寸、相对位置及压比和转速的影响。计算表明,矩形凹槽宽深比是影响凹槽篦齿封严性能的重要参数,当宽深比大于临界值时,相对于光滑齿的封严效率可大幅提升到15％左右。凹槽与篦齿间的轴向相对位置在一定范围内对凹槽齿的泄漏系数影响微小。数据还显示,压比和转速对凹槽齿的封严性能影响微小。

Abstract:

To promote the leakage performance of labyrinth seal, numerical simulations on the flow and seal characters of straight through labyrinth seal with a rectangular groove on the still case were carried out. Data of vortex structure, leakage coefficient and seal efficiency for the grooved labyrinth seal were obtained and compared with that of a smooth labyrinth seal. The effects of groove sizes, relative position between groove and tooth, pressure ratio and rotating speed were studied. Results show that the most important parameter that influences the leakage performance of grooved labyrinth seal is the ratio of groove width over depth. The seal efficiency can be increased up to 15% when the width/depth ratio of groove is larger than a critical value. The influence of the relative position between groove and tooth is less important if only the groove is just located between two teeth. Data also reveal that the influences of pressure ratio and rotating speed on the leakage performance of grooved labyrinth seal are small.