207 密閉回転容器内の2次元渦の挙動

抄録

A visual experiment of cyclonic and anticyclonic vortices in a rotating frame were carried out. After working fluid was in rigid-body rotation, the vortices were induced by a rotating disk which had different rotation to the container and flushed with an upper lid. The vortices showed two-dimensional columnar motion due to Taylor-Proudman theorem. In our experiment as Kloosterziel et al. and Heijst et al. described, monopolar and tripolar vortices merged, however, as Rossby number increased the vortices lost its symmetry, and vortex structures were found to depend on Rossby number Ro = |Ω-ω| /2Ω and Ekman number Ek =ν / (2 Ω R ²), here ν was kinematic viscosity of working fluid, Ω and ω respectively angular velocities of the container and rotating disk reference to stationary frame, and R a radius of the rotating disk.