Evaluation of low power consumption and temperature drop potential in an aero-engine pre-swirl system for turbine performance improvement

Aero-engine pre-swirl system is an essential sub-system in favor of turbine rotor blade cooling and turbine thermal efficient enhancement. This study proposed a novel problem-solving method to promote the existing potential of low power consumption and temperature drop by structure improvement of pre-swirl system. Then, the flow and heat transfer mechanisms in the system are analyzed comprehensively to improve the system performance according to the theoretical evaluation and numerical simulation with experimental verification. Additionally, the multi-factor influencing characteristics is revealed to evaluate the temperature drop efficient of the new system based on the entropy analysis. Results shown that, the airflow angle of attack at the receiver hole inlet significantly affected the aerodynamic and thermodynamic performances of pre-swirl system with the lowest entropy increase of 19.06 J·kg⁻¹·K⁻¹ and the highest temperature drop efficiency of 0.57 occurred at an 0° angle of attack. The oblique runway-shaped receiver hole in the cover-plate cavity effectively outperformed the straight runway and long runway shaped types for promoting the system performance. After local structure improvement, the specific power consumption of pre-swirl system reduced by 1.01 kW/(kg/s) from −3.05 kW/(kg/s) to −4.06 kW/(kg/s), the entropy increase of pre-swirl system reduced by 9.69% from 61.90 J·kg⁻¹·K⁻¹ to 55.90 J·kg⁻¹·K⁻¹, and the temperature drop of pre-swirl system increased by 5.96% from 23.5 K to 24.9 K. Therefore, this study will provide a reference for the design of the pre-swirl system with improved performance to lift turbine efficient.