The influence of secondary aspiration process on sampling efficiency of thin-walled aerosol probes (experiments and analysis)

The problem of sampling of coarse aerosols from gas flows into thin-walled cylindrical probes facing the wind and at yaw orientation with respect to the wind is observed using the hypothesis of secondary aspiration of particles after their rebound from the external surface of a sampler. Experiments were carried out by the comparison method in a large low-speed wind tunnel of an open-jet type in order to measure aspiration efficiency A sub(e) for the wind velocity, sampling flow-rate and a thin-walled probe. The test aerosol (Lycopodium) was generated by a special installment and was transported through the Vitoshinsky nozzle into the test section of the wind tunnel.