ABSTRAKT

The focus of this paper is on the fluid mechanics and heat transfer at the stagnation flow region at the leading edge of a turbine cascade airfoil. The fluid mechanics analysis presented is based on the exact solution to the Navier-Stokes equation of Hiemenz for a plane stagnating laminar flow. The heat transfer analysis is based on Hiemenz flow and a stagnation point potential flow, which predict a lower and an upper bound for stagnation region Stanton numbers. Comparisons of data from selected studies of skin friction and surface pressure show that the Hiemenz solution correlates well with the results from a number of stagnation flow experiments. The stagnation point heat transfer from four turbine cascade studies were found to be bounded by an upper limit on the Stanton number predicted by stagnation point potential flow and a lower limit by Hiemenz flow. These upper and lower limits should provide a useful heat transfer tool for the turbine designer.