TURBULENT FLUID AND PARTICLE INTERACTION IN THE BOUNDARY-LAYER FOR CROSS-FLOW OVER A TUBE

The influence of solid particles on the flow characteristics of the bo undary layer for cross how over a tube has been experimentally studied . A phase-Doppler anemometer was used to measure the mean and fluctuat ion Velocities of both phases. Two separate tests were conducted with two particle size ranges (30-60 mu m and 80-150 mu m) and the freestre am velocity and solid mass loading ratio were fixed, allowing the effe cts of particle sizes on the shape of the mean velocity profile and on the turbulent intensity levels. The measurements clearly demonstrated that the larger particles damped fluid turbulence. For the smaller pa rticles, this damping effect was less noticeable. The measurements fur ther showed a delay in the separation point for two phase turbulent cr ossflow over a tube. (C) 1998 Elsevier Science Ltd. All rights reserve d.