Experimental investigation of mixed convection heat transfer and flow characteristicts of air for aiding and opposing flow conditions in a rectangular channel

In this study, mixed convection heat transfer and flow characteristics of air for aiding and opposing flow conditions in a rectangular channel are invesigated experimentally. Heat trasnfer and particle image velocimetry (PIV) experiments have been performed in a rectangular channel placed on a flat plate with a width of 60 mm and a length of 150 mm. The air duct is posioned at 0º, 45º, 90º, 135º, 180º, 225º ve 270º degrees. Experiments have been carried out under constant heat flux boundary condition, and the duct has been operated in the suction mode. In the study in which heat trasnfer and flow field experiments are carried out simultaneously Reynolds number has been kept in the range of 150 to 550. Velocity distributions are obtained by using particle image velocimetry (PIV) technique at three different placement angles. It has eben observed that heat transfer occurs at an angle of 90º where natural convection supports forced convection, while the lowest heat transfer occurs at 270º, which is the opposite. There is a %10 increase in heat transfer at 90º and a decrease of %6 at 270º.