In this work, natural convection heat flow from the heated tube to fluid has been presented. The density difference which occurs due to temperature variation is the main cause of the flow of fluid inside the tube. When fluid temperature rises due to surrounding conditions, then fluid starts to rise and the movement of adjacent colder fluid occurs to fill that gap. The natural convection method is commonly used in electronic equipment, where maximum numbers of equipment are placed on a single small board. If proper heat transfer does not happen from that board to the surroundings, then failure of the total system may occur. As the forced convection heat transfer method is not practically feasible for such small boards, the natural convection method is suitable for these cases. Properties of heat flow by the medium through the vertical tube and the method to enhance natural convection heat flow have been offered in this work. The vertical tube is made of composite aluminum (Al-Al Composite tube) which is a non-magnetic material having good thermal conductivity properties. For heat transfer from a heated system, aluminum is preferred because of its high strength-to-weight ratio, lightweight, non-toxic, and better corrosion resistance. The vertical tube is 50 mm in diameter, and its length is 550 mm. Ratio of length to diameter of the arrangement is 11. By controlling external voltage supply to the unit, a constant heat flux is sustained inside the wall of the tube. Internal rings are provided inside the test section having a dimension of 6 mm thickness having a square cross-section. Rings are placed inside the tube with equal spacing between them to enhance heat transfer.