Numerical Investigation on Effects of Leakage Flow on the Aerodynamic Performance of Turbine Stages[J]. 2018, 52(4): 63-69.
DOI:
Numerical Investigation on Effects of Leakage Flow on the Aerodynamic Performance of Turbine Stages[J]. 2018, 52(4): 63-69.DOI: 10.7652/xjtuxb201804009.
Numerical Investigation on Effects of Leakage Flow on the Aerodynamic Performance of Turbine Stages
Effects of the different leakage flows on the aerodynamic performance of a three-stage test turbine are numerically investigated to improve the aerodynamic design of a real turbine. The three-dimensional Reynolds-Averaged Navier-Stokes(RANS)and the S-A turbulence model are used to analyze the leakage flows from the rotor tip clearance
the clearance between the stator hub and shaft
and the clearance between the rotor root and wheelspace disk. Results show that the three-stage turbine efficiency decreases by about 0.62% when the rotor tip clearance and the stator/shaft clearance are considered
however
the efficiency rises 0.28% by considering the rotor root and wheelspace disk clearance leakage flow through a comparison with the case that only considers rotor tip and stator/shaft clearance leakage flow. The rotor root and wheelspace disk clearance leakage is beneficial for improving efficiency of turbines to some extent. The flow direction of the mainstream and the leakage flow at the hub is influenced by the leakage from the rotor root and wheelspace disk clearance. The distribution and development of the secondary flow is influenced by the “suction” and “leakage” near endwalls
causing the change of energy loss coefficient in endwall regions.
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references
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