On the Choice of Coordinates Used to Describe Thermoelectric and Thermomagnetic Generators

Abstract

It is demonstrated that the form of the energy-dissipation equation which describes thermoelectric and thermomagnetic generators is greatly dependent on the choice of dependent variables in the coupled equations used to describe the devices. If “natural” coordinates are chosen, the energy dissipation will always contain two terms—the Fourier conduction term and Joulean heating term. If “unnatural” coordinates are chosen, the energy-dissipation equation will contain three terms. A brief solid-state consideration demonstrates how a bound on the figure-of-merit temperature product can arise in terms of fundamental physical parameters.