Numerical simulation of coupling heat transfer in sealed airborne electronic equipments

For shielding radio frequency and electromagnetic interference, the sealed case is usually used for airborne electronic equipment. As electronic products become faster and incorporate greater functionality, their thermal characters must be well analyzed and designed. Three-dimensional thermal numerical simulations from inside to outside of the sealed case were performed to get a clear sight of the coupling heat transfer in conduction, natural convection, and radiation. Temperature field, fluid flow field, and local heat transfer coefficient layout outside the wall were got, which were compared with the outcomes of the empirical method. The results of numerical simulation showed that in sealed case conduction was the dominant way, and natural convection had the comparative ratio with radiation, both of them were less than 25%. The maximum error of no radiation including could get to 43.2%.