Reactive infiltration instability

Reactive infiltration instability is the positive feedback in which reaction or melting increases permeability of a porous medium, focuses more reacting fluid into that region, and further increases permeability. Finite reaction-zone thickness, transport, and pore geometry can change the short-wave behavior; Interacting length scales in the reactive-infiltration instability analyzes transport and reaction length scales in a dissolution model.

A planar advection-driven melting front in a porous matrix with permeabilities $k$ ahead and $k+\Delta k$ behind has the ideal sharp-front growth rateThis follows by matching harmonic pressure perturbations and normal Darcy flux, then converting flux to front speed by the enthalpy balance. It predicts no finite fastest-growing wavelength when $\Delta k>0$.