Convective corrections to the linear diffusion equation.
The classical problem of the diffusion of heat in a homogeneous medium is reexamined, the medium being confined by fixed boundaries maintained at a fixed temperature. When the thermal diffusivity is small, the relaxation of the temperature of the medium to that of the boundary proceeds on two time scales, one associated with a lightly damped high-frequency acoustic mode and the other with an aperiodically damped diffusive mode. Considering for simplicity a spherical configuration, it is shown that the latter does not obey the classical linear heat conduction equation.
Department of Physics, University of California, Los Angeles, California 90049, USA.
Seth
S
Putterman
Paul
P
Roberts