放射状液膜流れの乱流くさび周辺の層流域で成長する斜行トルミーン・シュリヒティング波について(流体工学,流体機械)  [in Japanese] On the Growth of Oblique Tollmien-Schlichting Wave in Laminar Region Around a Turbulent Wedge Produced in a Radial Liquid Film Flow(Fluids Engineering)  [in Japanese]

This paper describes the formation and development of oblique Tollmien-Schlichting waves around a turbulent wedge in a radial liquid film flow. The liquid film flow was formed of water discharged to the atmosphere from a narrow gap between the end of a vertical cylindrical pipe and the surface of a horizontally placed disk. The turbulent wedge was generated artificially in the laminar region of the liquid film flow by two kinds of introduction of local turbulence : an isolated roughness element and a jet injection. Oblique T-S waves around the turbulent wedge were observed carefully by means of high-speed photography. In addition to the observation, downstream development of T-S wave produced by the local turbulence was simulated on the basis of a linear stability theory. The wave length and phase velocity of the oblique T-S wave and the manner of development of the oblique T-S wave observed experimentally were in good agreement with the simulation. This indicates that the oblique T-S waves around the turbulent wedge were not produced by the turbulence of the turbulent wedge, but produced by the local disturbance induced by the roughness element or the injection jet