On the Jet-driven Axisymmetric Thin Liquid Film over a Spinning Disc
نویسنده
چکیده
We consider the steady laminar annular spread of a thin liquid film generated by a circular jet impinging perpendicularly in direction of gravity on the centre of a horizontally rotating disc (figure 1). The individual flow regimes arising due to the largeness of the Reynolds number formed with the radius of the jet, its slenderness, and the relative magnitude of the centrifugal force measured by a suitably defined Rossby number Ro are examined both analytically and numerically. Matched asymptotic expansions of the flow quantities provide the proper means to clarify open issues concerning the asymptotic structure of the developed viscous film. A careful analysis of jet impingement predicts a negligibly small influence of gravity and surface tension on the film flow, considered in the spirit of a shallow-water approach. Accordingly, associated downstream conditions are disregarded due to two essential properties of the flow:
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