Jennifer S. Curtis, University of Florida, Chemical Engineering Department, P.O. Box 116005, Gainesville, FL 32611-6005 and Kunn Hadinoto-Ong, Division of Chemical and Biomolecular Engineering, Nanyang Technological University, 62 Nanyang Drive Blk N1.2 Level B2-31, Singapore.
This presentation will review existing ‘rules of thumb' for fluid-phase turbulence modulation in the presence of a dilute concentration of particles, such as found in pneumatic conveying systems. These ‘rules of thumb' relate turbulence modulation behavior to turbulent eddy length scale or particle Reynolds number. However, experimental data indicate that turbulence modulation is dependent on additional variables such as the macroscale Reynolds number. For example, it has been shown that gas-phase turbulence intensity which is attenuated with respect to the single phase flow at low Reynolds number, for a given particle loading, is then enhanced at higher Reynolds number. Hence, turbulence modulation behavior is much more complex than described by the simple rules of thumb. This presentation will review some of the new data on turbulence modulation and discuss some new possible mechanisms for the physical origin of fluid turbulence modulation behavior.