Internal convection in thermoelectric generator models

Coupling between heat and electrical currents is at the heart of thermoelectric processes. In a thermoelectric system this may be seen, from a thermal viewpoint, as an additional thermal flux linked to the appearance of an electrical current. Since this additional flux is associated with the global displacement of charge carriers in the system, it can be qualified as convective in opposition to the conductive part related to both phonon transport and heat transport by electrons under open circuit condition as, e.g., in the Wiedemann-Franz relation. In this article we demonstrate that considering the convective part of the thermal flux allows both new insight into the thermoelectric energy conversion and the derivation of the maximum power condition for generators with realistic thermal coupling.