The Impacts of Air Flow and Leg Geometry on Thermoelectric Generator Performance

In this study, the effect of thermoelectric leg geometry, heat sink and as an innovation, air flow on the performance of Thermoelectric Generators (TEGs) is investigated based on Comsol Multiphysics simulations. For this aim, while a temperature of 350 K was applied to one side of the thermoelectric (TE) module, a heat sink was added to the other side of the module to increase the temperature difference between the surfaces. The studies on thermoelectric generators in the literature have predominantly focused on heat sink geometry, fin structures or materials and module optimization. In this study, contrary to the existing literature, the effect of leg geometry on the electricity generation performance of a thermoelectric generator was analyzed in conjunction with various laminar air flow parameters, and the optimal geometry were determined. Exposing to the same heat source and keeping total volumes of the thermoelectric legs equal is essential to directly observe the effect of leg geometry on electricity generation performance and efficiency. When the results obtained in terms of electricity generation are compared to the rectangular leg structure which is most used in TE modules, it is seen that the TEGs with cylindrical, truncated prism, inverse truncated prism, truncated cone and inverse truncated cone legs produce approximately 9.69%, 14.68%, 16.74%, 12.9% and 19.97% electricity, respectively. When compared in terms of efficiency, it was concluded that the inverse truncated cone was 22.26% more successful than the conventional rectangular leg geometry.