Local convection heat transfer coefficient for a two-dimensional wall jet with uniform heat flux boundary condition using infrared imaging

The performance of automotive windshield defrosters is important for passenger safety and comfort. An experimental system was developed and used to generate benchmark data for a model heated wall jet flow using conditions relevant to automotive windshield defrosters as a means to aid defroster and defogger design.; The focus of this study was to measure the local heat transfer coefficient in the developing region of the wall jet with a uniform heat flux boundary condition. An infrared imaging system was used to measure the surface temperature field. The results were non-dimensionalized and compared to available literature data. The local convective heat transfer coefficient decreased rapidly from the jet exit plane to a minimum at approximately 4 jet slot widths (x/w), increased to a maximum at approximately x/w = 11. 5 and then decreased. The local convection heat transfer coefficient, hx, of the isoflux boundary condition was compared with that of an isothermal boundary condition using the same experimental system. The difference in hx was largest at the leading edge of the heated wall and decreased in the streamwise direction.