DISSIPATIVE STRUCTURE IN CONCURRENT-UP GAS-SOLID FLOW

The necessary condition for the formation and dissolution of the dissi pative structure in particle-fluid two-phase flow has been investigate d, revealing its origin in the compromise between the movement tendenc ies of the particles and the fluid. As soon as either the particles ca n dominate the fluid, or the fluid can dominate the particles, the dis sipative structure either dissolves or a newly formed coexisting unifo rm structure appears. At this transition point, operating conditions a nd material properties alone become insufficient to ensure the steady state. Quantification of such a complicated structure calls for some m ode of multiple resolution, for instance, it could be resolved with re spect first to scale and then to amplitude and periodicity. (C) 1998 E lsevier Science Ltd. All rights reserved.