バブルリングと通常渦輪の渦核領域構造の比較

抄録

Bubble ring is a well-known phenomenon such as a belga can produce a single bubble ring and, also, separate it to two rings, etc. To clarify the cause of stable durability, we studied on the flow structure of bubble and ordinal vortex ring. An axisymmetric two-dimensional numerical simulation was conducted in terms of ordinal vortex ring and three kinds of bubble rings in the conditions of same initial flow field. As a result, the flow filed of bubble ring transit to free vortex structure from the arbitral initial condition immediately. It was deduced that bubble played a role of a singularity, and it leads to stable movements of bubble ring. Afterwards, the temporal circulation was estimated to evaluate viscous loss. The circulations of bubble rings were higher than vortex ring. This result is attributed to the dissipation near the bubble-water interface.