Abstract: The flow characteristic in a cover-plate pre-swirl system in the turbine cavities was investigated by a simulation experiment in lower rotation speed.The distributing of pressure and velocity was measured in different turbulent flow parameters(0.5<λT<0.96) and swirl ratio(1.03<βp<1.9).The variety of pre-swirl ratio in the two cavities was obtained.The effect of rotational Reynolds number and pressure ratio of pre-swirl nozzles on the discharge coefficient of nozzles was analyzed.The results of this experiment show that the pressure rise due to centrifugal effect was obvious.The effect of the flow from the outlet of pre-swirl nozzles to the pressure and velocity of pre-swirl cavity was more than the flow from the receiver hole to the cover-plate cavity.The pressure ratio and rotational Reynolds number have litter influence on the discharge coefficient of nozzles.

Key words: Turbine wheel;Rotating disk;Rotor-stator system;Flow field measurement;Pre-swirl ratio

摘要： 通过低转速的模拟实验对涡轮盘腔的带盖板预旋系统的流动特性进行了研究。在不同的紊流参数(0.5<λT<0.96)和旋转比(1.03<βp<1.9)下测量了预旋腔和盖板腔内的压力与速度分布,得到了两个腔内的旋转比变化情况,并分析了旋转雷诺数和进出口压比对预旋喷嘴流量系数的影响。实验结果表明:在两个腔内离心升压效应明显,预旋喷嘴出口气流对预旋腔内的气流压力和速度的影响要远大于接收孔出口气流对盖板腔的影响,压比和旋转雷诺数对喷嘴流量系数有较小的影响。

关键词: 涡轮盘;旋转盘;转-静系统;流场测量;旋转比