The flow of thermal energy from matter occupying one region in space to matter occupying a different region in space is known as heat transfer. Heat transfer can occur by three main mechanisms: conduction, convection, and radiation. Physical models involving conduction and/or convection only are the simplest (Modeling Conductive and Convective Heat Transfer), while buoyancy-driven flow or natural convection (Buoyancy-Driven Flows and Natural Convection), and flow involving radiation (Modeling Radiation) are more complex. Depending on your problem, Ansys Fluent will solve a variation of the energy equation that takes into account the heat transfer methods you have specified. Ansys Fluent is also able to predict heat transfer in periodically repeating geometries (Modeling Periodic Heat Transfer), therefore greatly reducing the required computational effort in certain cases.