EXPERIMENTAL INVESTIGATION OF A 2-DIMENSIONAL CYLINDRICAL SAMPLER

A particle trajectory tracing method is used to measure the aspiration efficiency of a two-dimensional cylindrical sampler at various orient ations relative to the freestream flow direction. The experiments are performed at three different velocity ratios (U(o)/U(s) = 0.36, 1 and 1.43) and five different angles (0, 30, 45, 60 and 90-degrees). U(o) i s the freestream velocity and U(s) is the sampler suction flow velocit y. The particle sizes included in the study range from 20 to 60 mum in aerodynamic diameter. When the sampler is facing the wind (0-degrees) . the experimental data are in very good agreement with previous numer ical calculations and previous semi-empirical model predictions. Based on the experimental data, an improved model is obtained for angles fr om 0 to 90-degrees by modifying slightly the currently accepted semi-e mpirical model.