Control port influence on swirl, operating, and flow characteristics of a mini-vortex amplifier on glove box service

Abstract

The influence of control port geometry on swirl development, operating characteristics, global flow and momentum characteristics is studied experimentally. Shape and size of the control flow channels and the pressure applied at the tangential ports are critical in determining the trajectory of the jet issuing from the tangential ports; and deflection of radial flow, vortex strength and prevention of back diffusion along the radial supply ports. Dominance of control-to-exit area ratio is confirmed but a clear improvement in performance is noted for the practical site-based geometry that is not derived from this ratio, but from the shaped passages of the device. Flow and momentum characteristics provide additional design data. Lack of influence of supply-to-exit area ratio is demonstrated at lower ratios than advertised in literature. The relationship of Swirl number to output flow is demonstrated. The results imply a geometrical development that has led to practical improvements in vortex amplifier geometry on the scale of the mini-VA. Global flow and momentum characteristics provide insight into design and operation that is useful when avoiding back-diffusion in a mini-VA.