BEHAVIOUR OF BEDS OF DENSE PARTICLES IN A HORIZONTALLY OSCILLATING LIQUID.

WHEN A BED OF DENSE SOLID PARTICLES IN A HORIZONTAL TUBE IS SUBJECT TO AN OSCILLATORY LIQUID FLOW, FIVE DIFFERENT 'FLOW REGIMES' CAN BE IDENTIFIED, RANGING FROM A STATIONARY BED REGIME TO A COMPLETE SUSPENSION OF THE PA%TICLES IN THE LIQUID.IN THIS INVESTIGATION, THE TRANSITIONS BETWEEN THESE REGIMES HAVE BEEN MEASURED AS A FUNCTION OF THE FOLLOWING VARIABLES: ANGULAR FREQUENCY GW %2.5 TO 9 RAD/S<, AMPLITUDE A %UP TO 41 CM<, PARTICLE DIAMETER D %100 TO 1100 MM<, THE RATIO GG OF THE DENSITY DIFFERENCE BETWEEN PARTICLES AND LIQUID TO THE DENSITY OF THE LIQUID %0.26 TO 4.1< AND THE KINEMATIC VISCOSITY OF THE LIQUID V %0.89 TO 80.6 CST<.TWO FURTHER CONDITIONS WERE CONSTANT, NAMELY THE VOLUME CONCENTRATION OF SOLIDS %2 PERCENT< AND THE DIAMETER OF THE TUBE %5.08 CM<.LTHE AMPLITUDE-FREQUENCY THRESHOLD AT WHICH GENERAL SURFACE MOTION OF THE PARTICLES FOR PART OF THE OSCILLATION CYCLE WWAS FIRST OBSERVED COULD BE CORRELATED AS FOLLOWS:LAGW/SUP 1.5///SUB %/GG/SUB G