PSEUDO-SOLITONS IN FLUIDIZED-BEDS

An equation to describe a weakly unstable region of a uniformly fluidized bed in both gas solid mixtures and liquid-solid mixtures is derived from a two-fluid model by applying the reductive perturbation method. Our reduced equation near the transition point from stable fluidized beds to unstable ones is the Korteweg-de Vries equation. When the state is away from the critical point the effects of dissipations become important. The validity of our reduced equation has been confirmed by our numerical simulation.