Natural Convection Heat Transfer of Suspension in a Rectangular Vessel Heated from a Vertical Wall and Cooled from the Opposite One

Natural convection heat transfer of suspension in a rectangular vessel heated from a vertical wall and cooled from the opposite one was investigated. The suspensions were mixtures of water and SiO2 fine particles of 3 or 6 μm in mean diameter. The particle size distributions were narrow. The temperature and particle concentration distributions in the suspension and the average heat transfer coefficient on the vertical wall were measured under various conditions : temperature difference between the heat transfer walls, initial particles concentration, the mean diameter of particle and the width of the vessel. Comparing Nusselt number of the suspension to that of water, it was found that sedimentation of particles affected strongly the natural convection of suspension. Then the natural convection was classified into three types according to the intensity of convection. Effects of the experimental parameters on the natural convection phenomena and the Nusselt number were clarified.