Remarks on paper by Y. Bachmat and J. Bear, 'The general equations of hydrodynamic dispersion in homogeneous, isotropic, porous mediums'

The recent paper by Bachmat and Bear [1964] summarizes very nicely the results of recent investigations of the problems of dispersion in porous mediums. One of the fundamental concepts of the theory is that the dispersion tensor Dik may be expressed as the double contraction of a fourth-order geometrical dispersivity tensor αiklm and a second-order velocity tensor ulum/u. The theory as it now stands is applicable only to homogeneous isotropic mediums, i.e., ones in which αiklm is isotropic. At present there appears to be no extension of these results to anisotropic mediums.