The quality of large semiconductor crystals grown from silicon melts is significantly affected by the heat and mass transfer in the melt. The characteristics of silicon flows are reviewed by focusing on the Coriolis force in the rotating melt. Description of flow instability is included that shows our level of understanding of melt convection with a low Prandtl number.

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Vortical flows of electrolytes induced by the interaction of a localized steady magnetic field with electric currents and their present status of research are reviewed. In particular, “wake” flows induced behind a localized magnetic-field source moving at constant velocities will be described in some detail, and their relations with other fluid-dynamical problems will be discussed.

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An experimental study to examine the receptivity of a laminar boundary layer to an acoustical disturbance is conducted. The response of the forced oscillations of a Blasius boundary layer over a flat plate model caused by an acoustical disturbance is investigated for frequencies of 70Hz-85Hz. The most important aspect of the present investigation is to determine the behaviour of the disturbance in the boundary layer caused by the receptivity mechanism, and document accurately the acoustical forcing field.
First, the effect of leading edge geometry was examined using two different elliptical profiles. After examined favorable leading edge geometry to the receptivity mechanism, a thin two-dimensional roughness strip is placed across the span of the plate. Such experimental condition provided a receptivity mechanism together with acoustical forcing by a loud-speaker. The measured disturbance profile corresponded to the T-S wave amplitude predicted by linear stability theory. The phase distribution and the wavelength of the disturbance are also in good agreement with predicted values.

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In order to achieve the high pressure and high temperature by cylindrically converging shock wave, axially symmetrical shock wave is widely considered to be more effective than non-symmetrical shock wave. Numerical simulations in this paper clarifies the effect of non-symmetricity of shock waves on the highest pressure achieved near the central axis. It is found that the proper amount of the non-symmetricity of shock wave leads to higher pressure near the central axis compared to the completely symmetrical shock wave.

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Computer analysis of video pictures of tufts attached on the surface of a high speed train rear end body was carried out to investigate the wake of the train. The video pictures were digitized and loaded frame-by-frame into a harddisk of a computer using a video editor. Each picture frame was analyzed by the computer to identify angles of the tufts in the picture. From the time-series of angle data of the tufts, statistical data were obtained. Periodicity was found in the movements of the tufts, but the frequencies differed by the location. Antisymmetric periodic motion indicating an alternating shedding of large scale vortices was found when the movements of tufts averaged over a wide area on each side of the end body were analyzed.

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