Rectangular Slit Atmospheric Pressure Aerodynamic Lens Aerosol Concentrator

Figures & data

TABLE 1 Design parameters for 2D ADL simulation

	Slit 1	Slit 2	Slit 3
Particle size (and St)	5 μm (St = 0.54)	2 μm (St = 0.53)	0.8 μm (St = 0.52)
Slit wetted diameter (Re)	1740 μm (Re = 858)	710 μm (Re = 832)	300 μm (Re = 884)
Slit width dimension	900 μm	360 μm	150 μm
Average velocity	7 m/s	17 m/s	42 m/s

FIG. 1 Top: velocity magnitude (m/s) contours for 2D numerical simulation of the aerodynamic lens. Inset, lower left: flow streamlines (gray lines with arrows), and 0.8 μm particle trajectories (black lines).

FIG. 2 Major flow inlet design.

FIG. 3 3D CFD simulation of prefocusing inlet section. Particle size is 10 μm: black tracks are passed through the prefocusing section; white tracks originate downstream uniformly distributed over the flow cross-section.

FIG. 4 Effect of the focusing inlet on concentration efficiency of aerodynamic lens.

FIG. 5 Calculated collection efficiencies.

FIG. 6 Experimental and modeled collection efficiency of the ADL concentrator for Reynolds numbers of 800–900. Major/minor flow splits are: (top) 20:1; (middle) 50:1; (bottom) 100:1.

TABLE 2 50% cut-off particle size for ADL concentrator

Minor/major flow split	20:1	50:1	100:1
CFD predicted cutoff particle size, μm	0.6–0.7	0.7–0.8	0.8–0.9
Experimental cutoff particle size, μm	<0.8	1.0	1.0–2.0

FIG. 7 Measured concentration ratio of ADL concentrator.