Annular Jets of Different Diameter Ratios

Abstract

Summary This paper describes part of a detailed study of annular jets of different diameter ratios. From the overall pressure and spectral measurements of conical and basic annular jets of five diameter ratios the coherent structures of the standing vortices, wake vortices, jet vortices, lower wake induced vortices and wake induced vortices can be isolated and their effects assessed. The findings are supported by the available multi-exposed schlieren photographs of both the conical and basic annular jets. The causes for the presence or absence of the additional trains of vortices in the jet flow can also be evaluated by the variation of the diameter ratio. For the standing vortices and wake vortices within the flow behind the interface good correlation is found with the available pressure behind the interface.