Impact of Wall Temperature on Heat Transfer Coefficient and Aerodynamics for Three-Dimensional Turbine Blade Passage

摘要

The present work is aimed to examine how the heat transfer coefficient (HTC) and main three-dimensional (3D) passage aerodynamic features may be affected by a nonadiabatic wall temperature condition. A systematic computational study has been first carried out for a 3D nozzle guide vane (NGV) passage. The impacts of wall temperature on the secondary flows, trailing edge shock waves, and the passage flow capacity are discussed, underlining the connection and interactions between the wall temperature and the external aerodynamics of the 3D passage. The local discrepancies in HTC in these 3D flow regions can be as high as 30-40% when comparing low and high temperature ratio cases. The effort is then directed to a new three-point nonlinear correction method. The benefit of the three-point method in reducing errors in HTC is clearly demonstrated. A further study illustrates that the new method also offers much enhanced robustness in the wall heat flux scaling, particularly relevant when the wall thermal condition is also shown to influence the laminar-turbulent transition exhibited by two well-established transition models adopted in the present work.