ONE-DIMENSIONAL AEOLIAN SUSPENSION ABOVE BEDS OF LOOSE PARTICLES - A NEW CONCENTRATION-PROFILE EQUATION

The theoretical solution for concentration profiles of particles in aeolian suspension above large beds of loose particles is re-examined. It is argued that the solution generally found in the literature is based on an erroneous boundary condition at the surface of the particle bed. A revised boundary condition is suggested and this leads to a new equation for particle concentration profiles in the one-dimensional zone. The profiles are a two-parameter family. The parameters are the ratio of particle settling velocity to wind friction velocity and a concentration ratio. Crude estimates of the latter parameter are available from a formula derived in the paper. The new profile equation is supported by experimental data. Also, unlike the old equation, it gives the expected logarithmic concentration profiles in the limiting case of very fine particles.