The pre-swirl system can offer cooling air to improve the extreme thermal shock to the rotating turbine blades in a gas turbine engine. This study focuses on theoretical, experimental, and numerical analyses about the flow and entropy increment for a pre-swirl system at the high-speed test conditions (up to 10000 rpm). Especially, the pre-swirl system entropy increment was firstly measured in the experiment. Then, the experimental test and CFD analysis are conducted to reveal the pressure ratio characteristics and loss mechanism. Research suggests that the non-dimensional temperature drop and the rotating Mach number are major determinants for the ideal pressure ratio. However, the ratio of the actual system pressure ratio to the ideal pressure ratio only depends on the entropy increment. For a given rotating Mach number, the actual system pressure ratio decreases with the non-dimensional temperature drop increasing. The increment of mass flow rate results in an enhancement in the entropy increment. In addition, the entropy increment of the receiver hole can be minimal for the swirl ratio of pre-swirl nozzle outlet close to 1. Therefore, this study can provide the basis for designing and optimizing the pre-swirl system at a high rotation speed.

预旋流系统可以提供冷却空气，以改善对燃气涡轮发动机中旋转的涡轮叶片的极端热冲击。这项研究的重点是在高速测试条件（最高10000 rpm）下对预旋流系统的流量和熵增量进行理论，实验和数值分析。特别是，在实验中首先测量了旋流前系统的熵增量。然后，进行了实验测试和CFD分析，揭示了压力比特性和损失机理。研究表明，无量纲温度下降和旋转马赫数是理想压力比的主要决定因素。但是，实际系统压力比与理想压力比之比仅取决于熵的增量。对于给定的旋转马赫数，实际系统压力比随无量纲温度降的增加而减小。质量流量的增加导致熵增加的增加。此外，对于预旋流喷嘴出口的涡流比接近​​1的情况，接收孔的熵增量可以最小。因此，本研究可以为设计和优化高转速的预旋流系统提供基础。