Heat Transfer due to Natural Convection from Parallel Vertical Plates

The heat dissipation from two parallel plates vertically held in free air is experimentally studied. From the Schlieren photos taken under various conditions of S (spacing of two plates) and ΔT (temperature difference between the heated surface and environment), the temperature gradients over the surface are evaluated and the local heat transfer coefficients : αx are calculated. An experimental formula representing the mean Nusselt number is obtained.[numerical formula] for [numerical formula] where [numerical formula] H : height of plate. The physical properties at the wall temperature are considered. A comparison is made between the result of this work and the experimental works of Kennard and Elenbaas.