Aerodynamic Design and Performance Analysis of the Ultra-High Expansion Ratio Turbine for Trans-Media Engines

EasyChair Preprint 6354

Abstract

In order to produce more specific work in trans-media engines, which features low-mass flow feeding systems, the flow loss of ultra-high expansion turbine with single stage need to be studied further. In this paper, the numerical method was used to carry out calculations for turbines in both air and underwater working conditions, and the flow fields inside the flow passage of ultra-high expansion ratio turbines are studied in detail. The results show that the power, efficiency and flow requirements of the engine in the air condition and underwater conditions can be met by changing the number of nozzles and the throat area while keeping the blades unchanged. In underwater working conditions, shock waves are formed obviously between one nozzle outlet and suction surfaces of three rotor blades, while in the air conditions, shock waves are only formed between one nozzle outlet and suction surface of two rotor blades . Therefore, overall, the efficiency in the underwater condition is significantly less than that in the air condition. In the both conditions, the gas in the blade passage corresponding to the circumferential gap between the two nozzles generates vortices due to mutual mixing, resulting in vortex losses.

Keyphrases: Aerodynamics, Trans-media engine, Ultra-high expansion ratio turbine, shock wave

@booklet{EasyChair:6354,
  author    = {Siyu Wu and Jie Gao and Cheng Zhou and Weiliang Fu},
  title     = {Aerodynamic Design and Performance Analysis of the Ultra-High Expansion Ratio Turbine for Trans-Media Engines},
  howpublished = {EasyChair Preprint 6354},
  year      = {EasyChair, 2021}}