Experimental investigation of dilute turbulent particulate flow inside a curved [formula omitted] bend

Abstract

The behaviour of dilute turbulent particulate flows inside a curved 90 ∘ bend was investigated experimentally in the Advanced Laser Diagnostic Laboratory at CSIRO Division of Minerals. Mean and fluctuating velocities of gas and particulate phases have been obtained using 2D Laser Doppler Anemometry (LDA). Glass spheres with mean dimeter of 77 μ m were used to represent the solid phase and they were released into a square-sectioned duct, where air was flowing at a bulk velocity of 10 m / s ( Re = 102 , 000 ) . Significant gas–solid separation was detected near the outer wall of the duct. This region is characterised by a considerable positive slip velocity between the two phases. In the inner-wall region, gas and solid velocities were almost identical and this suggests an extinction of coarse particles in the area. The level of velocity fluctuations in the solid phase was higher than that of the gas phase at the bend entrance and this possibly pointed to an early formation of particle rope.