2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/27679Conventional methods for the simulation of diffusive systems are quite slow when applied to strongly inhomogeneous systems. We present a new hierarchical approach based on dynamic renormalization-group ideas and on the Walsh transform (or Haar wavelet) of signal-processing theory. The method is very efficient for simulation of petroleum reservoirs or other strongly inhomogeneous diffusive or pressure-driven flow systems. In a test case, the hierarchical method is found to achieve 1.5% accuracy roughly 25 times faster than conventional finite difference methods.6 pages, 4 postscript figures, uses psfig to include the postscript figuresCondensed Mattertext