An experimental investigation of the heat-transfer effects of a longitudinal vortex embedded in a turbulent boundary layer

Longitudinal vortices occur in numerous flow situations in which heat transfer is of considerable importance, such as on the endwalls and blade surfaces of turbine cascades. Previous research implies that the heat transfer rate is increased in the region of these vortices. However, most of these investigations have involved complex turbulent flows in which the longitudinal vortices are just a small component of the total flow configuration. The purpose of this experimental investigation is to isolate the specific effects of longitudinal vortices on heat transfer by embedding a single longitudinal vortex in an otherwise two-dimensional turbulent boundary layer. By obtaining spatially resolved heat transfer measurements and detailed fluid mechanical data, the local effects of the longitudinal vortices on the transfer rate will be determined, as well as the fluid dynamic mechanisms which cause these changes.