Numerical and experimental thermal performance analysis of two different types of air cooled electronic chassis developed for military aviation platform

Because of exposing challenging environmental conditions such as extreme ambient temperatures, high humidity, salt fog and dust, electronic units in military systems have substantially different design constraints than others. Hence it should be taken serious precautions to prevent electronics and mechanics from these environmental threats. This study is aimed to provide numerical approach to tackle the extreme environmental conditions and obtain high cooling performance for an electronical device. In accordance with the purpose, two different chassis design alternatives have been proposed. First, cold plate fin (heat sink) design is carried out with several fin type iterations considering the temperature and pressure drop values and it gives rise to a compact product with high cooling rate. Second, using the exactly the same fin configuration, the chassis is externally cooled where corrugated plain fin (air to air HX) is used to make the unit as bright as possible with easy production. In mechanical aspect, both designs are very different from each other but they serve the same purpose using the same electronic components, cold plates and cooling fan. All numerical analysis have been carried out by using ANSYS Fluent ® software and prototypes are tested in the laboratory by measuring the temperature at critical points. Besides, in terms of engineering point view, advantages and disadvantages of both designs are discussed in detail.