Tien Symposium
Secondary Flows in the Blade-Endwall Region of a Turbine Cascade
H. P. Wang, S. J. Olson and R. J. Goldstein
Symposium on Thermal Science and Engineering
in Honor of Chancellor Chang-Lin Tien
University of California, Berkeley, California, Nov. 14, 1995.
Experimental flow visualization and mass transfer measurements have been conducted to describe the three-dimensional flow field near the endwall of a turbine cascade. Variations in the naphthalene mass transfer rate on the blade surfaces are explained with the aid of smoke wire and surface flow visualization techniques. A region of increased mass transfer rate, caused by the passage vortex system is found on the downstream region of the suction surface near the endwall. Local variations in the mass transfer rate are found to correspond to upwash and downwash regions formed by the secondary flow field. On the pressure surface, a three-dimensional separation is found near the leading edge of the blade. The combination of mass transfer and flow visualization results complement one another and allow a detailed description of the three-dimensional flow field.
Steve Olson (sjo@me.umn.edu)