Effects of the Distance Between Heat Transfer Plates on Free Convection Heat Transfer in a Stably Stratified Fluid Between Vertical Plates

An experimental study was performed on the effects of the distance between heat transfer plates on free convection heat transfer in a stably stratified fluid between vertical plates. The stratified layer was formed using a sucrose aqueous solution, and was heated from one sidewall at constant heat flux and cooled from the other sidewall at constant temperature. The experiments were conducted for the distance between the heat transfer platesl=10 mm, 20 mm, 40 mm and 60 mm. As a result, it was found that the average heat transfer coefficient deceases with an increase in the distance between the heat transfer plates, when the cellular convection layers do not fully develop and heat conduction prevails in the heat transfer. On the other hand, it was found that after the cellular layers have fully developed, the average heat transfer coefficient becomes great in the case of the thickness of the cellular layer being close to the distance between the heat transfer plates.