13.1 Introduction

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 methods: conduction, convection, and radiation. Physical models involving conduction and/or convection only are the simplest (Section  13.2), while buoyancy-driven flow or natural convection (Section  13.2.4), and radiation models (Section  13.3) 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 (Section  13.4), thus greatly reducing the required computational effort in certain cases.