Papers Published

  1. Howle, Laurens E. and Behringer, Robert P. and Georgiadis, John G., Visualization of natural convection in ordered and disordered porous layers, American Society of Mechanical Engineers, Fluids Engineering Division (Publication) FED, vol. 172 (1993), pp. 387 - 395 .
    (last updated on 2007/04/06)

    Abstract:
    The recent Modified Shadowgraphic Technique is used to study pattern formation of convecting flows in fluid saturated porous layers. Both regular and random media are explored, each exhibiting distinct primary bifurcation behavior. In regular porous layers, consisting of grids of overlapping bars, the preferred wave pattern at onset is parallel rolls with roll orientation determined by bar orientation at the upper and lower boundaries. The random medium shows a different disorganized convection pattern with each cycling through the onset of convection. The experimental work is complemented by large scale numerical simulation of large aspect ratio convection in porous layers with uniform permeability and with spatially varying permeability. The influence of the permeability field on pattern selection is explored.

    Keywords:
    Heat convection;Porous materials;Flow interactions;Computer simulation;Mechanical permeability;