Affiliation:
1. Lund Institute of Technology
Abstract
In the present work, a numerical study has been performed to simulate the effect of free-stream turbulence, length scale and variations in rotational speed of the rotor on heat transfer and fluid flow for a transonic high-pressure turbine stage with tip clearance. The stator and rotor rows interact via a mixing plane, which allows the stage to be computed in a steady manner. The focus is on turbine aerodynamics and heat transfer behavior at the mid-span location, and at the rotor tip and casing region. The results of the fully 3D CFD simulations are compared with experimental results available for the so-called MT1 turbine stage. The predicted heat transfer and static pressure distributions show reasonable agreement with the experimental data. In general, the local Nusselt number increases, at the same turbulence length scale, as the turbulence intensity increases, and the location of the suction side boundary layer transition moves upstream towards the blade leading edge. Comparison of the different length scales at the same turbulence intensity shows that the stagnation heat transfer was significantly increased as the length scale increased. However, the length scale evidenced no significant effects on blade tip or rotor casing heat transfer. Also, the results presented in this paper show that the rotational speed in addition to the turbulence intensity and length scale has an important contribution to the turbine blade aerodynamics and heat transfer.
Reference31 articles.
1. Denton, J.D., 1974, “A Time Marching Method for Two-Dimensional and Three-Dimensional Blade to Blade Flows”, ARC R&M 3775.
2. Sieverding C. H. , 1985, “Recent Progress in the Understanding of Basic Aspects of Secondary Flows in Turbine Blade Passages”, ASME J. Engineering for Gas Turbines and Power, 107, pp. 248–257.
3. Langston S. , 2001, “Secondary Flows in Axial Turbines - A Review”, Heat Transfer in Gas Turbine Systems, Annals of the N.Y. Academy of Sciences, 932, pp. 11–26.
4. Dunn M. G. , 2001, “Convective Heat Transfer and Aerodynamics in Axial Flow Turbines”, ASME J. Turbomachinery, Vol. 123, pp. 637–686.
5. Amano, R.S., Song, B., Sitarama, S., and Lin, B., 1998, “Predictions of Turbulent Flow in a Turbine Stator/Rotor Passage”, ASME GT-1998-524.