Geometrical considerations in the Control and manipulation of conductive heat flux

We indicate the fundamental rationale underlying the control of temperature and the manipulation of thermal flux, with reference to a multilayered composite material. We show that when the orientation of the layers in the composite is physically rotated with respect to a constant temperature gradient, there would then be a corresponding introduction of off-diagonal components in the thermal conductivity tensor and thermal anisotropy is induced. The consequent bending of the heat flux lines is found to depend on both the (i) composite rotation angle, as well as the (ii) ratio of the thermal conductivities of the constituent materials.