Abstract
A relatively small reservoir, fixed with its axis horizontal, was supplied with water through two tangential pipes symmetrically disposed. Thence the swirling water passed through a convergent-divergent nozzle to a long Perspex tube, in which measurements of the stream were made. Inviscid theory suggests that the radial thickness of the stream discharged from the nozzle is independent of the supply head. This prediction was confirmed by observations with two nozzles having different throat diameters, but the measured thicknesses were greater than the theoretical. Turbulent jumps were formed in the tube by means of a conical obstruction at outlet. The nozzle with the larger throat produced a second, much feebler jump. Again, the measured thicknesses of the stream below the jump were greater than the theoretical. A jump of this kind could provide a compact means of bringing a liquid into violent contact with a gas and separating it afterwards from any gas not absorbed.