STABILITY OF DISPLACEMENT OF A COLD FLUID BY A HOT FLUID IN A POROUS-MEDIUM

The stability of nonisothermal flow through porous media is investigated, when both density and viscosity variations with temperature are present. The instability phenomena are due to the buoyancy effect of a density gradient directed upward, and to the fingering effect of the displacement of a more viscous fluid by a less viscous one. Small perturbations are superimposed on the basic flow, and their development is investigated in order to establish the criteria of flow stability. The flow variables are expanded in a series of eigenfunctions, and the ensuing system of ordinary differential equations is solved numerically. Criteria of flow stability and parameters affecting flow conditions are studied. © 1979 American Institute of Physics.