The general equations of hydrodynamic dispersion in homogeneous, isotropie, porous mediums

The general equations governing the hydrodynamic dispersion of a homogeneous fluid in a homogeneous and isotropic porous medium are described. The flow is saturated and steady, but not necessarily uniform. The equations are first stated in Cartesian coordinates. A general equation in tensorial form is then derived for nonuniform flow in any coordinate system. Finally, the equation is expressed in a simplified form in a curvilinear orthogonal coordinate system of which one family of coordinate curves coincides with the family of streamlines. Some two- and three-dimensional cases serve as illustrations.