This study presents experimental and numerical investigation for three-dimensional heat transfer
characteristics in a turbine blade. An experimental set-up was installed with a turbine cascade of
five blade channels. Blade heat transfer measurements were performed for the middle channel under
uniform heat flux boundary conditions. Heat was supplied to the blades using twenty-nine electric
heating strips cemented vertically on the outer surface of the blades. Distributions of heat transfer
coefficient were obtained at three levels through blade height by measuring surface temperature
distribution using thermocouples. To understand heat transfer characteristics, surface static pressure
distributions on blade surface were also measured. Numerical investigation was performed as well
to extend the investigation to locations other than those measured experimentally. Threedimensional
non-isothermal, turbulent flow was obtained by solving Reynolds averaged Navier
Stokes Equations and energy equation. The Shear stress Transport k-ω model was employed to
represent turbulent flow. It was found through this study that secondary flow generated by flow
deflection increases heat transfer coefficient on the blade suction surface. Separation lines with high
heat transfer coefficients were predicted numerically with good agreement to the experimental
measurements. |
