Abstract: For the results that how preswirl structure influences the flow characteristics of a coverplate system，the experiment has been carried out for different pre-swirl angles and inlet positions of a cover-plate system. Static pressure distribution on the stator，total pressure distribution and swirl ratio on the mid plane，the discharge coefficient of pre-nozzle and the flow resistance coefficient in cavity were obtained under high rotating speeds. The results show that the pressure values and pressure distributions in the cavity are affected by pre-swirl angles and inlet positions，respectively. Swirl ratio on the mid plane increases with pre-swirl ratio increasing，and there being a linear variation between swirl ratio and dimensionless radius -2 powers in rotor-stator cavity. The discharge coefficient of pre-swirl nozzle increases with the increase of pressure ratio. The flow resistance coefficient increases with the turbulent flow parameter increasing，and decreases as rotational Reynolds number increasing.

Key words: Cover-plate；Pre-swirl angle；Inlet position；Rotor-stator system；Pre-swirl cavity；Flow

摘要： 为探究预旋结构如何影响盖盘系统内的流动特性，对不同预旋角度和进气位置的带盖盘预旋系统进行实验研究，得到了高转速下静盘表面静压和中心面总压的分布、中心面旋流系数、预旋孔排气系数以及腔内流阻系数。结果表明:预旋角度和进气位置分别影响腔内压力分布大小和分布趋势。随预旋比增加中心面旋流系数整体增加，转静腔内旋流系数与无量纲半径的-2次幂存在线性关系。预旋孔排气系数随预旋孔进出口压比的增加而增加。流阻系数随湍流参数增大而上升，随旋转雷诺数的增加而减小。

关键词: 盖盘；预旋角度；进气位置；转静腔；预旋腔；流动