Abstract
Growth process and three-dimensional deformation process of the disturbance wave which appears in the laminar-turbulent transition process of a radial liquid sheet flow are clarified. The radial liquid sheet is formed by the release of a radial liquid film flowing on a disk from the edge of the disk to still air. When the Reynolds number is large, a concentric disturbance wave appears and grows downstream on the free surfaces of the liquid sheet. The disturbance wave is caused by the unstable disturbance which is attribute to a inflectional velocity profile inside the liquid sheet. The detailed observation of the disturbance wave, which is excited by supersonic wave, reveals that the growth process and the three-dimensional deformation process of the disturbance wave.
