Natural convection around a vertical cylinder (thermal probe) immersed in a porous medium

Natural convection around a vertical cylindrical, immersed in a fluid-saturated porous medium, is investigated experimentally. The porous medium is made of glass beads with particles of the same diameter, 3 mm, and is saturated with water. The vertical cylinder, with diameter of 1.5 mm and long 150 mm, is a thermal probe, containing an electric heater and a thermocouple. Natural convection around the vertical cylinder is investigated experimentally with the help of three temperature sensors, at different heights on the external surface of the cylinder. Average and local Nusselt numbers along the vertical cylinder are calculated and compared with the available theoretical-numerical data of the literature.