Unsteady Effects of Upstream Nozzle Wakes on Hub-Endwall Flow and Heat Transfer of an HPT Rotor

Publish Year: 1398
نوع سند: مقاله ژورنالی
زبان: English
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شناسه ملی سند علمی:

JR_JAFM-13-2_011

تاریخ نمایه سازی: 15 دی 1400

Abstract:

Nozzle wakes have significant effects on the heat transfer on the rotor blade and endwall surfaces. Numerical studies have been carried out in a subsonic high pressure turbine stage to investigate the rotor’s secondary flow field and endwall heat transfer. Both steady and unsteady RANS analyses were accomplished for the multiple blade rows using mixing-plane and domain-scaling techniques respectively. Special attention was focused on the particular nozzle wake structure of secondary passage vortex near the hub endwall and its effects on the endwall heat transfer characteristics. Unsteady solution indicates that the passage vortex near the rotor hub is transported toward the midspan due to the blade interaction and rotation effects. In the front passage region, the time-averaged result yields higher heat transfer up to ۲۰% than a steady one, and the transient fluctuation amplitude reaches ۴۰% of mean values along the passage vortex moving path. In the rear passage region, the difference between steady and unsteady solutions is negligible. Current study reveals that the major difference of wake effects between an actual turbine and a linear cascade with moving bars comes from the movement of the vortical endwall passage vortex in the incoming flow.

Authors

L. Chen

School of Energy and Power Engineering, University of Shanghai for Science and Technology, Shanghai ۲۰۰۰۹۳, China

Z. F. Lu

School of Energy and Power Engineering, University of Shanghai for Science and Technology, Shanghai ۲۰۰۰۹۳, China

R. Dai

School of Energy and Power Engineering, University of Shanghai for Science and Technology, Shanghai ۲۰۰۰۹۳, China