Calculation of concentration of aerosol particles around a slot sampler

A mathematical model and numerical procedure are proposed for investigation of aspiration efficiency and the particle concentration field around a slot sampler in a moving gas. A potential-flow model for the carrier gas and a Lagrangian method for calculation of particle trajectories and concentration are employed. The particle concentration patterns around the slot and at the sampler inlet are studied. The dependence of the aspiration efficiency on the ratio of the wind and sampling velocities is analyzed. It is shown that the local aspiration efficiency calculated on the symmetry axis of the slot gives satisfactory approximation for the integral aspiration efficiency.