Flow Characteristics of an Air-particle Rectangular Jet with Particle Dynamics Analyzer

摘要

In an air-particle test facility, a particle dynamics analyzer (PDA) was used to measure the flow characteristics of an air-particle rectangular jet. Profiles of velocities, particle concentrations, particle sizes and turbulence characteristics were measured simultaneously. The length of the potential core zone was as long as five times of the half-width of the jet. The particle inertia has a great effect on the axial velocity attenuation of particles. The distribution of air-particle axial velocities is similar and coincides with Gauss distribution. In the down jet, it coincides better with Richard formula. The distribution of particle concentrations is similar to that of velocities. The attenuation of the maximum axial volume flux is larger than that of maximum axial velocities. In the near field of the jet the mass diffusion is larger than the velocity diffusion. The profile of Reynolds tangential stresses has a peak value in the boundary layer, where the ambient medium and the air-particle jet have a large momentum interchange. The outlet condition of the jet and the interaction of particles have a great effect on the turbulent kinetic energy.