In the engineering field, the design of a component with a material distribution that guarantees the best performance is one of the most crucial optimization problems. Topology optimization has been developed to provide an innovative method of design that accounts for defined objectives to be optimized and constraints to be respected, resulting in a procedure that is faster than the standard process of design, test and re-design loop. This approach was first investigated for structural optimization, however, the idea is applicable to any situations where the physics problem can be expressed by partial differential equations, which broadens its applications to a wide range of different fields such as heat conduction, electromagnetism and also fluid flow, where it is still in its early stages of development.