EXPERIMENTAL MEASUREMENTS OF HEAT-TRANSFER COEFFICIENT IN A PARTIALLYFULLY OPENED TILTED CAVITY/

An experimental investigation was carried out to determine the hear tr ansfer coefficient from a rectangular tilted cavity to the ambient due to the buoyancy driven flow in the cavity. The cavity is partially or fully open from one side. All the walls of the cavity are adiabatic e xcept the wall facing the cavity opening which is heated at a constant heat flux. Air was used as the cavity fluid and the experiments were carried out at a flux Grashof number of 5.5 x 10(8). The tilt angle of the cavity, measured from the vertical direction, was changed between -90 deg to +90 deg in 15 deg increments. Also, geometries of aspect r atio (height-to-width of cavity) of 1.0, 0.5, and 0.25 and of opening ratio (opening height to cavity height) of 1.0, 0.5, and 0.25 were con sidered in the study. The results are presented in terms of the averag e Nusselt number for different values of the above experimental parame ters. Conclusions are derived for the effect of changing the tilt angl e, the aspect ratio, or the opening ratio of the cavity on the average hear transfer coefficient between the cavity and the ambient air.