Thermal Anisotropy in Injection Molded Polymer Composite Fins

An integrated molding-heat transfer modeling methodology is used to study the thermal characteristics of polymer composite fins subjected to convective heat transfer coefficients. Numerical predictions of the fiber orientation in a representative, injection-molded plate fin, based on the Folgar-Tucker model, are used, via the classic Nielsen model, to determine the anisotropic variation of thermal conductivity in the fin. Thermal simulations are then performed to determine the effect of both global and local thermal anisotropy on the temperature distribution and heat transfer rate of the anisotropic fin. It is also shown that the harmonic mean conductivity, in the axial direction, can be used to represent the heat loss of an anisotropic fin to better than 10% accuracy.