The development of high-performance thermal systems (e.g., electronic component cooling, heat management in space vehicles, etc.) has driven the need for methods to improve heat transfer. The study of improved heat transfer performance is referred to as heat transfer enhancement, augmentation, or intensification. Enhancement techniques can be classified as passive (requiring no direct application of external power) or as active schemes (requiring external power). The most commonly used passive heat transfer enhancement scheme is the use of extended surface devices. These are usually in the shape of fins that project out of the body or tube that requires cooling. The amount of cooling is dependent on the size and geometry of the fins as well as on the type (air, or liquid) and speed of the flow through them. Extended surface heat transfer enhancement is one of the fastest growing technologies in heat transfer research and development.