Analysis of Low Pressure Turbine Flow at Low Reynolds Number

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Year:
2021
Type of Publication:
Article
Keywords:
Low Pressure Turbine, Numerical Simulation, Reynolds Number, Boundary Layer Separation, Total Pressure Loss
Authors:
YUE Long
Journal:
IJAIM
Volume:
9
Number:
6
Pages:
110-117
Month:
May
ISSN:
2320-5121
Abstract:
In order to understand the flow mechanism of low-pressure turbine flow field at low Reynolds number in more detail, the SST k-ω turbulence model was used to conduct numerical simulation research on low-pressure turbine at 0.6×105 Reynolds number. It is found that at low Reynolds number, the viscous effect of airflow is more significant, and the boundary layer on the endwall is thicker. Closed-type separation occurs at 75%Cax at the rear of the cascade, and gradually changes to open separation along the direction of blade height. The thickness of separation bubble also increases. The existence of separation bubble significantly increases aerodynamic loss. Under the joint action of adverse pressure gradient and viscosity, the thickness of the low-speed zone on the suction surface at the rear of the cascade gradually increases along the direction of blade height. The absolute value of vorticity at the junction of the low-speed zone and the main flow zone is larger, which is the main area where aerodynamic losses are generated. In the process of developing downstream, passage vortexes and corner vortexes are constantly involved in more low-energy gases with increasing sizes, which are important sources of aerodynamic losses of low-pressure turbines.
Full text: IJAIM_641_FINAL.pdf

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