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Showing papers on "Marangoni effect published in 1978"


Journal ArticleDOI
TL;DR: An experimental verification of Marangoni convection in the liquid inter-space between two-coaxial discs is carried out at reduced gravity effect using small Bond's number obtained by choice of small characteristical diameter.

102 citations


Journal ArticleDOI
TL;DR: In this paper, the onset of surface tension driven stationary circulation in a thin film flow down a heated incline is studied by use of linear theory, and it is shown that the flow structure corresponding to the neutrally stable state is that of stream-wise oriented vorticies.

37 citations


Journal ArticleDOI
TL;DR: In this article, the stability conditions for experiments in standard and reduced-gravity conditions when the Soret effect is operating in a horizontal binary liquid layer heated from below and open to the ambient air were given.

36 citations


Journal ArticleDOI
TL;DR: In this article, the authors used high speed flash cine photography of talc particles on the surfaces of both laminar and turbulent jets to obtain the surface ages of pure water and dilute solutions of surface active agents.
Abstract: Experimental values of the surface velocities vs of water jets have been obtained by high speed flash cine photography of talc particles on the surfaces of both laminar and turbulent jets. Values of the surface ages as defined variously by Defay and Hommelen (1958), Hansen (1964), and Harper (1973) have been obtained from our data for both pure water and for dilute solutions of surface active agents. We find, by comparison with published entry length corrections for gas absorption, that x/vs gives the most reasonable age of the surface at any distance x along a jet of pure water. If a surface active agent is present in the water, the amount of adsorption of a few millimeters downstream from the nozzle is of the order ten times greater than calculated for laminar jets and five to six times greater than calculated for turbulent jets at Ren = 18 800. This we ascribe to liquid circulation in the jet adjacent to the nozzle, caused by the Marangoni surface flow, which also reduces vs significantly.

19 citations


01 Oct 1978
TL;DR: In this article, the transition from the steady to the oscillatory Marangoni convection in a floating zone under reduced influence of the gravity is visualized by means of the already proved method of light-cut-technique.
Abstract: The transition from the steady to the oscillatory Marangoni convection in a floating zone under reduced influence of the gravity is visualized by means of the already proved method of “light-cut-technique”. The Marangoni convection is caused by a negative temperature gradient from the upper to the lower copper plug, whose diameter is kept to a small magnitude of 3 mm Φ to obtain a small Bond's number. By this way the micro-gravity effect in respect to the Marangoni convection can be simulated. From the visualization and the simultaneous measurements of the local temperature the range of the Marangoni number for the transition is determined. A strong correlation exists between the observed period of the oscillation of the branching streamline between the two vortices on the plane with the axis of the floating zone on one hand and the period of the temperature oscillation on the other hand. A model conception for the physical mechanism is introduced to understand this oscillatory instability.

18 citations


01 Sep 1978
TL;DR: In this article, the authors presented a study for the onset of convection in a solidifying system in an environment which is similar to that encountered in space processing, where the only driving mechanism considered is that due to the variation of surface tension force at the free surface of the melt layer.
Abstract: The low gravity environment of Earth's orbit is being seriously considered for experimentation on the production of materials in space Most of such materials processes inevitably involve either the solidification of melt or the melting of solids Inherent in most fluid mechanisms with temperature gradients is convective motion A study is presented for the onset of convection in a solidifying system in an environment which is similar to that encountered in space processing Since the study is for a low gravity condition, the only driving mechanism considered is that due to the variation of surface tension force at the free surface of the melt layer Two simple solidification models were considered, one in which the solidification process enters in the perturbation system and another in which the melt is solidifying at a constant rate The results show that the solidification process will bring about convection in the melt earlier than otherwise

1 citations


Journal ArticleDOI
TL;DR: In this article, the authors treated the fluid dynamics aspects for material science experiments with respect to purely space experiments and preparatory experiments on the ground, and the following subjects may be treated: convection phenomena, capillarity and kinetics of liquids.

1 citations


Journal ArticleDOI
TL;DR: In this paper, the stability problem of a viscoelastic fluid layer of integral type was investigated by the Fourier method during heating from below and the simultaneous effect of the lift and thermocapillary forces was taken into account.
Abstract: The stability problem of a viscoelastic fluid layer of integral type is investigated by the Fourier method during heating from below. The simultaneous effect of the lift and thermocapillary forces is taken into account. The critical values of the Rayleigh and Marangoni criteria are determined.