This research project consists of the numerical and experimental analysis of heat transfer by natural convection from heated surfaces containing wavy surface. The wavy surface considered in this study may be square, rectangular, triangular or sinusoidal, having the effect of increasing the heat transfer rate from a heated surface to an adjacent fluid. The main objective of this project is to determine the increase of the heat transfer rate by natural convection to the ambient air from horizontal and inclined heated surfaces with wavy surfaces only on one side of the surface and on both sides of the surface with respect to same smooth surface without wavy surface. The effects of the wavy surface type, the variation of the wavy surface height and the Rayleigh number will be analyzed. These problems will be solved numerically using the k-epsilon turbulence model with the help of commercial software ANSYS FLUENT ©. The experimental results will be obtained in a more restricted way, with experimental models being made of solid aluminum with triangular wavy surface of constant height and a set of thermocouples mounted inside the solid to allow the determination of its temperature using the lumped capacity method. According to the results obtained, recommendations can be made such as the location, height and shape of the wavy surface which provide the greatest improvement in the heat transfer rate by natural convection from a heated surface.