Title: Dispersion in heterogeneous nonuniform anisotropic porous media
Description: The objective of this project is to study the theory and measurement of dispersion during miscible flow in heterogeneous nonuniform anisotropic porous media. An understanding of the dispersion phenomenon is necessary to predict flow of miscible fluids in non-homgeneous porous media. A significant literature review of dispersion in non-homogeneous porous media was accomplished. The continuum and statistical theories of flow in porous media were studied. A series of experiments in models of unconsolidated porous media were run to study the effects of heterogeneity, nonuniformity, and anisotropy on dispersion. The non-homogeneities are defined in relation to permeability of the media and dispersion coefficients are correlated with respect to permeability. Tracer output curves from models were interpreted for dispersion. Dispersion changes significantly with permeability. When models of different permeability are connected, the dispersive effect is not reciprocal. Dispersion changes significantly with nonuniformity. Likewise there is a significant effect when models of different nonuniformity are interconnected (second-order heterogeneity). Anisotropy was included in two kinds of models (linear and radial) by packing alternate layers of beads causing flow through these layers at different angles. The usual dispersion model is not adequate for "block box" prediction of the tracer output curve for data on anisotropic shperes. The results have immediate practical applicates, especially in tracing of contaminents in surface and subsurface flow such as movement of pesticides, fertilizers, acid mine drainage, feed-lot waste, etc. through the soil.
Subjects: Dispersion, Laminar flow, Mixing, Porosity, Controlled Environment