Gradient-dependent heat rectification in thermoelastic solids

We study heat rectification by means of application of an inhomogeneous distribution of a tensile mechanical stress in: (a) graded thermoelastic systems with constant cross section; (b) non-graded thermoelastic systems with variable cross section. In both cases the thermal conductivity of the material may be partially tuned by the internal strain produced by the application of transversal mechanical stress. We calculate the rectification coefficient (Formula presented.) as function of different control parameters, such as applied strain, stoichiometry, geometry, external heat flux. In the case (a) we consider three different graduations (Formula presented.) in the case (b) three different internal strain distributions (Formula presented.) with L 1 the length of the system and (Formula presented.) 0 a constant strain. In both cases we show that, the higher n, the higher the rectification coefficient. We have also considered how the rectification depends on (Formula presented.) 0, whose value may be easily controlled from the outside, thus allowing some degree of control on the rectification coefficient.