Abstract: This article makes an experimental study of gas-phase turbulence modulation by particles with different material density in small particle Reynolds number range. The gas-phase velocity and turbulence intensity are measured by means of a phase Doppler particle analyzer (PDPA) in a gas-particle round turbulent jet. The measured results of gas-phase velocity and turbulence intensity are compared when the jet is laden with glass or polyethylene particles of the same size and shape respectively. The particles volume fractions are approximately the same in the experiments. It is found that particles with different material densities have the same influence on the mean decaying velocity, while they have different influences on the turbulence intensity. In the near-fields, the gas-phase turbulence intensities are augmented more by glass particles with larger density than polyethylene particles with smaller density. In the far-fields, the gas-phase turbulence intensities are attenuated by particles and glass particles with larger density have a more pronounced effect on the attenuations of turbulence than the lighter polyethylene particles. The present study provides the theoretical reference and guidelines for proposing reasonable flow controlling methods of two-phase round turbulent jet.

Key words: turbulence modulation, particle material density, gas-particle two-phase flow, round turbulent jet, phase Doppler particle analyzer