In the wake of rapid shrinkage of electrical systems, thermal management of electrical systems has become the central area of focus in research and development in the field of electronics. A failure in providing sufficient heat dissipation (cooling) in an electronic device such as a computer or a smartphone can lead to temporary or even permanent breakdown of the device, due to the occurrence of extremely high temperatures in different parts, such as printed circuit boards (PCBs), central processing unit (CPU) or disk drives, which results in malfunctioning of these components. Engineers must give a high priority to thermal management in the design process of electrical devices. An accurate CFD modeling and analysis of the heat transfer mechanisms in such systems lead to cost-effective and optimum designs. Using heat transfer analysis using ANSYS Fluent, a designer can find out these concepts. First, how much heat dissipation we require. Second, what the most efficient cooling method is, and third, which components are overheated once the system has a specific heat source.