Design of cellular structures for optimum efficiency of heat dissipation

Metal cellular material is a new material attractive for its light weight and potential multifunctionality. In the present paper, we study cylindrical structures made of linear metal cellular material. The outer surface of the cylindrical structure is subjected to thermal boundary condition, and cooling fluid is forced through the cylinder to remove heat through the inner cell walls. Optimum design aims at maximization of heat dissipation efficiency under prescribed flow pressure. Two classes of design variables, relative density, and local aperture distribution of cellular material are to be determined by optimization under given total material volume constraints. Although similar to the structural topology optimization concept of material distribution, our formulation results in a structure with realistic cellular material of finite-sized aperture. Numerical results for different cross-sectional shapes and thermal boundary conditions are presented. Interestingly, our present formulation leads to optimum designs for cellular structures that mimic natural biomaterials. We discuss in general the guideline for cellular structure design to maximize heat dissipation efficiency based on insights from these optimization results.