Generation and Propagation of Undamped Temperature Waves under Pulse Action on a Target Surface

The physical mechanism of undamped temperature waves and the conditions of generation thereof in media with a finite time of local thermal relaxation are examined. The wave frequency depends on the relaxation time and the parameters of the pulse action on a medium, and the lowest frequencies corre spond, in particular, to air. These effects can be used to identify and investigate this action. It is demonstrated that the character of wave reflection from the interface between different media depends on the state and the finish quality of the given surface. In particular, in the ideal case of a sharp interface between air and metal, temperature waves are totally reflected at the interface. On the contrary, if there is a “blurred” interface, reflections can be almost completely suppressed and waves not absorbed in air penetrate into another medium and are rapidly attenuated in it. Other combinations of media can also lead to an analogous phenomenon, which makes it possible to develop remote heating systems by which distant environments are warmed with out thermal energy losses in the intermediate medium.