Aerosol deposition in a pipe with turbulent airflow

摘要: There are many theories to predict turbulent aerosol deposition in a pipe. Experimental data available only for small pipes (Dp < 3 in.) and low Reynolds Numbers (Re 100,000). The purpose of this work was experimentally measure the micron-size particles on wall 6-in. pipe which an moving under flow conditions. Turbulent completely developed, were as high 367,000. A wind tunnel constructed establish developed Homogeneous, monodispersed aerosols Uranine-Methylene Blue at charge equilibrium produced by spinning disc generator. Experiments performed with spherical ranging size from 0–44 2–16 μm projected area diameter. The introduced into tunnel, both average centerline mass number concentrations measured point onto 1-in. annulus tunnel. At site deposition, flux, based particle number, determined. In order theoretically calculate airflow conditions characteristics upstream site. Initial problems system led conclusion that electrically charged may increase thirtyfold factor, even when aluminum is grounded. Existing underpredicted factors 10,000. Independent measurements during same experiment differed no larger than 2 or 3, thus ruling out experimental errors source discrepancies between theory experiment. It concluded that: (1) Present underpredict flow. (2) Particle dimensionless velocity strongly dependent upon Number. (3) not correlated relaxation time. (4) Additional related needed.