Flow of Dilute Suspensions of Particles Around Axisymmetric Baffles

摘要

Measurements of the streamwise mean and r.m.s. velocity components were presented for the two-phase flow of 27 micrometers mean diameter solid particles in water behind two axisymmetric baffles, a conical baffle of 25% area blockage and a disk-shaped baffle of 50% area blockage, for particle concentrations up to 1.5% by volume. The mean velocity results show that for a concentration of solids of 0.375% by volume the particles in general follow the fluid motion behind the conical baffle but the annular jet region behind the disc-shaped baffle is narrower in the presence of the particles, in the recirculation zone the particle velocity profiles are flatter than those in single-phase flow. The measured turbulence levels in the presence of the particles are consistently lower than those of the fluid in single-phase flow. This suppression of turbulence varies in magnitude from 3-38% depending on the location in the flow. Measurements were made in both configurations with varying concentrations of particles of up to 1% in the disk and up to 1.5% in the cone configuration, and showed that the particle turbulence levels decreased as the concentration was increased.