Pumping effects due to reciprocating asymmetric baffles

A significant pumping effect at low differential head can be achieved by oscillating one or more asymmetric baffle plates in a tube. The resistance to backflow of fluid relative to the plates is affected by the direction of movement of the plates, for a given plate speed. This effect has been demonstrated in a 5 cm dia. tube, using an air-driven plate assembly at frequencies from 0.5 to 2.25 Hz and strokes from 10 to 25 cm. The forms of the …