Heat Dissipation Analysis And Design Of Ultra-light Cellular Materials And Electronic Equipment

As a new kind of multifunctional materials, two-dimensional cellular materials (also calledhoneycomb materials) attract a lot of interests. By designing the microstructure of thematerials, two-dimensional cellular materials can be suitable for the multifunctionalrequirement such as mechanics, heat dissipation, acoustical scattering and energy absorption,etc. With a single "easy flow" direction and larger surface area density, two-dimensionalcellular materials exhibit attractive thermal capability as well as the high specific rigidity andspecific strength. It is of great significance to study its heat dissipation characteristic throughforced convection.With the developing of the electronic equipment toward integration and miniaturization andthe increasing of the power density, thermal management becomes one of leading problemswhich restrict the development of the electronic equipment. Designing the equipment with abetter thermal structure to improve the heat dissipation capability and finally to reducetemperature of the important component has become a hot issue concerned by the electronicequipment designers.Thermal design of two-dimensional cellular materials and electronic equipment isdiscussed using the numerical simulation. The main works in this paper as follows:1. With the multifunctional design of two-dimensional cellular materials in mind, a newoptimization design concept is presented. The design parameters range (the acceptablerange of the design parameters which can satisfy the requirement) is maximized undergiven heat dissipation capability constraints. In a given geometry space filled withtwo-dimensional cellular materials composed of typical microstructures, the sensitivity ofthe microstructure size and porosity on the heat dissipation is researched and its reason isanalyzed. The best heat dissipation capability is obtained by optimizing the porosity andthe size of the microstructure. The maximum heat dissipation capability for the materialswith different cell morphologies is compared. Under given heat dissipation capabilityconstraints, design parameters range of the materials with different cell morphologies iscompared too. The analysis indicates that two-dimensional cellular materials with regularhexagonal cells provide the highest level of heat dissipation efficiency. Under given heatdissipation capability constraints, Hexagon uses the least material, has a larger designspace and is more suitable for the ultra-light multifunctional design. The ultra-light multifunctional capability of the Hexagon becomes more obvious as the demand of heatdissipation capability increases.2. In order to solve the problem that the acquisition of component heat dissipation is difficult,a new method based on the component operational temperature obtained by experimentand using the inversion technology to define the component heat dissipation is putforward. The optimization model of the component heat dissipation inversion isformulated. With the identification of the component heat dissipation of certain electronicequipment as an example, experiment test, numerical model of electronic equipment andnumerical computation of conjugate heat transfer in the process of applying inversiontechnology are discussed. The success of applying component heat dissipation inversiontechnology demonstrates the efficiency of the present method.3. Taking the thermal design of certain electronic equipment as an example, the convectionair cooling of electronic equipment in the system level is discussed. Under the constraintof unchanging the inner structures of the equipment, the distribution of the inlet vent andfans is designed to optimize flow field, which can improve the heat dissipation capabilityof the equipment. Two kinds of fans are compared. The relation between fan capabilityand the heat dissipation efficiency of the equipment is investigated. The results suggestthe rational distribution of the inlet vent and fans can improve the heat dissipation of theelectronic equipment significantly. The increase of numbers of the fans can improve theheat dissipation capability of the equipment only when the inner flow field is optimized.Meanwhile, increasing the fan power can improve the heat dissipation capability of theequipment, but its efficiency is not necessarily ideal.