Laser Doppler Anemometry Investigation of Single-Phase and Particle-Laden Jet Flows

摘要

An experimental investigation of the near field of an axi-symmetric single-phase and particle laden jets is described. A two-component laser Doppler anemometer was used to measure the turbulent flow characteristics. The second phase consisted of glass beads of 80 micrometer diameter with a mass loading of 1%. Typical flow Reynolds numbers were 29 000 at the jet exit. The measurements indicate that the particles lag behind the fluid by about 8% near the jet exit but lead the fluid by about 7% at 9 jet diameters downstream. The mean velocity profiles of the particle laden flow are flatter, exhibit lower radial rms velocities than those of the fluid and suggest a smaller spread of the beads in the cross-stream direction. Streamwise velocity fluctuations of the particles were found to be higher than the corresponding fluid fluctuations, especially near the jet exit, which can be attributed to the fan spreading of the particles. Keywords: Laser Doppler anemometry; Two phase flow. (jhd)