1019 MAXIMUM CIRCULATION OF A VORTEX RING GENERATED BY A PULSATING JET

抄録

The relationship between the circulation of cyclic vortex rings, which are generated cyclically by a pulsating jet, and jet pulsation conditions are investigated. First, a method for estimating the circulation of cyclic vortex rings is established based on experimental results. In this method, the formation time, i.e., the time it takes for the cyclic vortex rings to form completely, can be estimated using the self-induced velocity of the vortex rings and the convection velocity of the shear layer of the jet. If the total circulation generated by the jet up to the formation time is assumed to be acquired within the vortex core, then the circulation of cyclic vortex rings can be estimated using the slug flow model. The self-induced velocity of cyclic vortex rings and the convection velocity of the shear layer can be estimated based on the jet pulsation conditions. According to these estimation results, there exists a specific condition under which the circulation of the vortex rings becomes maximum.