A Design Tool for Aerodynamic Lens Systems

We report in this article the development of a tool to design and evaluate aerodynamic lens systems: the Aerodynamic Lens Calculator. This Calculator enables quick and convenient design of aerodynamic lens systems based on the parameterized knowledge gained from our detailed numerical simulations of flow and particle transport through aerodynamic lens systems. It designs the key dimensions of a lens system: pressure limiting orifice, relaxation chamber, focusing lenses, spacers and the accelerating nozzle. It also provides estimates of particle terminal axial velocities, particle beam width, and particle transmission efficiencies. This article describes in detail the information that is used in the design tool, including equations for pressure drop through orifices, contraction factors as a function of Reynolds, Mach and Stokes numbers, spacer length as a function of Reynolds number and estimations for the relaxation chamber dimensions. The article also evaluates the performance of the design tool by comparing its predictions with the performance of aerodynamic lens systems that have been described in the literature.