ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Control of thermocapillary convection in a liquid bridge by vibration (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 73 (1993), S. 4165-4170 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The streaming induced in a short vertical liquid column (L/R≤1, L: length, R: radius) by the vibration of one of the supporting end walls has been utilized in this novel study. Vibration essentially drives a surface flow in the zone away from the vibrating wall, with the return flow in the bulk towards the wall. Preliminary measurements of the surface streaming velocity show that it increases with the frequency and amplitude of vibration and the zone length, and decreases with the viscosity of the zone liquid. This controlled surface streaming has been employed to balance an opposing, steady thermocapillary flow in a model half-zone of silicone oil. In addition to the evidence gathered through flow visualization, temperature measurements in the zone reveal that the radial temperature gradients set up by the thermocapillary flow are weakened/offset by this balancing.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.352850
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Use of mechanical deflection to eliminate metallic vapor deposition on vacuum view ports (1994)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 65 (1994), S. 2406-2407 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: Metallic vapor emitted from a source can be deflected prior to depositing on an observation view port by imposing fans whose blades rotate perpendicular to the atoms flight path. The effectiveness of this technique is demonstrated with tin vapor in terms of relative rate deposition and visual examination as a function of the imposed rotation rate. The consequence of fan rotation on sample visibility is shown to be negligible.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1144695
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Extended 8.beta.(H)-drimane and 8,14-secohopane series in a Chinese boghead coal (1990)
    s.l. : American Chemical Society
    Energy & fuels 4 (1990), S. 177-183 
    Details
    ISSN: 1520-5029
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Energy, Environment Protection, Nuclear Power Engineering , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ef00020a009
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Stability of an acoustically levitated and flattened drop: An experimental study (1993)
    New York, NY : American Institute of Physics (AIP)
    Physics of Fluids 5 (1993), S. 2763-2774 
    Details
    ISSN: 1089-7666
    Source: AIP Digital Archive
    Topics: Physics
    Notes: This is an experimental study of the flattening and breakup of liquid drops in a single-axis acoustic levitation field, and is an extension of the authors' previous work [C. P. Lee et al., Phys. Fluids A 3, 2497 (1991); Proceedings of the 30th Aerospace Sciences Meeting and Exibit, Reno, NV (1992)], on the static shape and stability of acoustically levitated drops. Two aspects, namely (i) the variation of drop equilibrium shape with sound pressure level and, (ii) the mechanism of disintegration of small drops in intense sound fields, have been studied mainly with water drops. The drop-shape study reveals that the critical acoustic Bond number Ba,cr [Ba = A2Rs/(σρc2); A: acoustic amplitude; Rs: spherical radius of the drop; σ : surface tension of the drop liquid; ρ: density of air and; c: sound speed in air], at which a downturn in acoustic intensity occurs for the larger drops, or loss of stability occurs for the smaller drops, varies from about 2.6 (for kRs∼0.74; k: acoustic wave number) to about 3.6 (for kRs∼0.25). The corresponding nondimensional critical equatorial radius R*cr (R*=R/Rs, R: equatorial radius of the drop) varies between 1.5 and 1.4. The study also reveals that, for deformation R* greater than about 1.3, the drop assumes the shape of a disk. The study of the dynamics of disintegration of small drops reveals that, following loss of stability, the drop expands horizontally with the liquid close to the edge drawn into a sheet by acoustic suction. The sheet continuously thins during expansion and two types of waves, one in the azimuthal direction, and the other in the radial direction, are parametrically excited on it. The ensuing violent vibration shatters the drop; with the whole process having a time scale of the order of 0.5 msec. These results partially confirm the mechanism of drop disintegration postulated by Danilov and Mironov [J. Acoust. Soc. Am. 92, 2747 (1992)]. The parametric instability of the thin sheet differs from that of the well established Faraday instability of a liquid half-space, where the parametric oscillations are excited at half the frequency of the external field.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.858738
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    A theoretical model for the annular jet instability (1986)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Fluids 29 (1986), S. 2076-2085 
    Details
    ISSN: 1089-7666
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The instability of an annular gas-core liquid jet is modeled theoretically by treating the liquid layer as a membrane moving under the influences of its own inertia, surface tension, and the gaseous hydrostatic pressure difference between its two sides. Essential physical mechanisms are reconstructed without making any attempt to fit experimental data with model constants. The results compare favorably with those of experiment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.865594
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Oscillations of a compound drop system undergoing rotation (1985)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Fluids 28 (1985), S. 1023-1026 
    Details
    ISSN: 1089-7666
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A compound liquid drop system is comprised of three immiscible concentric fluids: a core fluid of density ρ(i) surrounded by a shell of density ρ(s) which is embedded in a medium of density ρ(0). In this analysis, the fluids are incompressible and inviscid. The effect of rotation upon the modes of oscillation of a compound drop is investigated. Rotation rate is considered as a small perturbation of the normal modes of the compound drop, thus introducing the effects of a Coriolis force and a centrifugal distortion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.865022
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Streaming generated in a liquid bridge due to nonlinear oscillations driven by the vibration of an endwall (1996)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Fluids 8 (1996), S. 3234-3246 
    Details
    ISSN: 1089-7666
    Source: AIP Digital Archive
    Topics: Physics
    Notes: It has been observed that streaming can be generated in a liquid bridge supported by two endwalls, with one wall vibrating to excite its capillary oscillations [Anilkumar et al., J. Appl. Phys. 73, 4165 (1993); Mollot et al., J. Fluid Mech. 255, 411 (1993)]. The finding has been applied to suppress thermocapillary convection in crystal growth using the float zone technique [Grugel et al., J. Cryst. Growth 142, 209 (1994)]. In this work we shall explain the mechanism that drives the streaming, for low streaming velocities, in terms of an "acceleration shear'' of the free surface of the liquid column. The results compare favorably with experiments with long columns. We have found that for a low viscosity liquid, the streaming pattern changes sign when the oscillation is adjusted from one side of a resonant peak to the other. This allows for more flexibility in the application of the streaming to counteract thermocapillary convection, during crystal growth in a float zone. We have also found that for low viscosities, the streaming velocity is inversely proportional to viscosity. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.869114
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    A theoretical model for centering of a thin viscous liquid shell in free and forced capillary oscillations (1996)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Fluids 8 (1996), S. 2580-2589 
    Details
    ISSN: 1089-7666
    Source: AIP Digital Archive
    Topics: Physics
    Notes: In previous numerical studies [Lee and Wang, J. Fluid Mech. 188, 411 (1988); Pelekasis et al., J. Fluid Mech. 230, 541 (1991)], it has been shown that when an inviscid and nonconcentric liquid shell undergoes a finite-amplitude capillary oscillation, its enclosed bubble undertakes a slow translational oscillation relative to the shell. In the present work, we study the effects of viscosity on the slow motion, in both free and forced capillary oscillations. It is found that in a free oscillation, the shell cannot become concentric because the oscillations are damped by viscosity before centering occurs. In a forced oscillation which is sustained by an external source such as a modulated acoustic radiation pressure, centering does occur when the slow oscillations are damped. The predicted centering of the shell takes place more slowly than that observed in experiments [Wang et al., J. Colloid Interface Sci. 165, 19 (1994)]. However, it is noted that a comparison with experiments is not appropriate at this time, since the shell in the experiments had an uncontrolled rotation in the acoustic potential well. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.869045
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Static shape and instability of an acoustically levitated liquid drop (1991)
    New York, NY : American Institute of Physics (AIP)
    Physics of Fluids 3 (1991), S. 2497-2515 
    Details
    ISSN: 1089-7666
    Source: AIP Digital Archive
    Topics: Physics
    Notes: There have been observations that an intense sound field can break up a liquid drop in levitation by flattening it drastically through radiation pressure. Using high-speed photography, it is observed that, for a low-viscosity liquid, at a high sound intensity, ripples appear on the central membrane of the drop. At a higher intensity, the membrane may atomize by emitting satellite drops from its unstable ripples. For a general viscosity, it might also buckle upward like an umbrella and shatter, or might simply expand horizontally like a sheet and shatter. Using a disklike model for the flattened drop, the phenomenon was studied and good qualitative agreement with the observations was found. It is believed that at low viscosity, the ripples are capillary waves generated by the parametric instability excited by the membrane vibration, which is driven by the sound pressure. Atomization occurs whenever the membrane becomes so thin that the vibration is sufficiently intense. For any viscosity, the vibration leads to a Bernoulli correction in the static pressure, which is destabilizing. Buckling occurs when an existent equilibrium is unstable to a radial oscillation of the membrane because of the Bernoulli effect. Besides, the radiation stress at the rim of the flattened drop, being a suction stress, is also destabilizing, leading to the horizontal expansion and the subsequent breakup.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.858192
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Surface-tension-induced mixing following coalescence of initially stationary drops (1991)
    New York, NY : American Institute of Physics (AIP)
    Physics of Fluids 3 (1991), S. 2587-2591 
    Details
    ISSN: 1089-7666
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The momentumless coalescence of drops of the same liquid, separated by an immiscible host, is studied experimentally. Observations show that for low-viscosity drops of unequal sizes, there is considerable mixing following coalescence, with the smaller drop penetrating the larger drop as a vortex. The extreme case of coalescence of a small drop with the bulk of the same liquid at a flat interface with an immiscible liquid is studied in detail. The penetration depths of small drops (1–5 mm) following coalescence are measured and correlated with theoretical predictions. It is found that in the range of the investigation, the penetration depth is proportional to the 5/4 power of drop diameter and inversely proportional to the square root of the drop viscosity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.858199
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...