ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

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
    [S.l.] : American Institute of Physics (AIP)
    Physics of Fluids 13 (2001), S. 2030-2044 
    ISSN: 1089-7666
    Source: AIP Digital Archive
    Topics: Physics
    Notes: It is shown analytically that different subgrid eddy viscosities are required to characterize the evolution of the velocity field, the energy spectrum and the dissipation rate, respectively. Also, a subgrid viscosity calculated recursively from the conditionally averaged "subgrid–subgrid" stress can only be used to renormalize the dissipation relation. It is also shown, by direct numerical simulation, that the spectral correlations of subgrid and resolved stresses are dominated by "resolved–subgrid" terms, in agreement with existing conclusions from energy transfer or other more global methods. We also note the low level of correlation between the exact subgrid stress and the eddy–viscosity model for all explicit–scales wave numbers. Lastly, we report results from a large-eddy simulation (LES) based on a recursively calculated effective viscosity and note that the results are about as good as for other subgrid models but underline the need to take account of phase effects as well as the dissipation rate. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 280 (1979), S. 45-46 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] The fibres used were chrysotile asbestos and are known to be very effective drag reducers. A nominal fibre concentration of 300 p.p.m. by weight was used throughout. Following the usual practice, the fibres were dispersed in 0.5% aqueous solution of Aerosol OT. Fig. 1 Mean velocity profiles in a ...
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 262 (1976), S. 47-48 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] The bubbles were produced by passing air through a submerged nozzle in a steel water-tank, 75 60 70 cm, which was mounted on an expanded polystyrene sheet (5 cm thick), on a concrete base. The compressed air supply consisted of a piston sliding in a cylinder. This was driven by an electric motor ...
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 292 (1981), S. 520-522 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Although there are many similarities between the effects of the two kinds of additive, they are thought to involve different mechanisms. For example, use of polymers and fibres together can produce much larger reductions in drag than would be the case with either additive On its own5. We have ...
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 273 (1978), S. 653-654 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Our experiments were carried out on a turbulent flow of water in a horizontal pipe of circular section. To ensure that the flow was well developed, the injection point was preceded by an entrance length. We injected relatively concentrated solutions of polyacrylamide (Separan AP 30) or ...
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 251 (1974), S. 598-599 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Our apparatus was made from clear PVC tubing (nominal bore 1.3 cm) mounted vertically on a wooden board. The tube was partially filled with liquid, thus creating a rudimentary manometer. The basic experiment consisted of giving the liquid column an initial displacement (25 cm in all cases) from ...
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 26 (1980), S. 1048-1049 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Aqueous solutions of polythyleneoxide (Polyox WSR-301) were injected into a pipe flow through either a small tube at the center line or an annular slot in the wall. The solution contained polymer at an injection concentration of 1,000 wppm. Injection into water flow with a Reynolds number Re = 3.5 × 104 was at a rate which gave a mean polymer concentration of 5.0 wppm in the water flow. A laser-Doppler anemometer (LDA) was used to measure the streamwise turbulent velocity at various radial positions and at several stations downstream from the injection point.Results were obtained for mean velocity and intensity profiles; autocorrelations; and one-dimensional energy spectra. The mean bursting period was determined using the “short-sampling-time” autocorrelation method. Changes in all these quantities due to polymer injection were found to depend on the amount of local drag reduction at that particular downstream station but were independent of the local polymer concentration at the measuring point.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 22 (1976), S. 603-604 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 28 (1982), S. 547-557 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Aqueous solutions of drag-reducing polymers were injected into turbulent water flow in a pipe. The injection point was situated where the flow was well-developed. Thus, subsequent steamwise variations in pressure drop were due to the injected polymer spreading out across the pipe. The axial development of local drag reduction was monitored by a series of closely-spaced pressure tappings. The corresponding radial dispersion of the injected polymer, as it travelled downstream, was assessed by sampling the flow at various points.Local drag reduction, due to either point injection at the centerline or injection through a slot in the wall, was found to increase with distance downstream. This increase was related to the streamline increase of polymer concentration in a narrow annulus near the pipe wall. It was tentatively concluded that the effective annulus was bounded by 15 ≤ y + ≤ 100, in agreement with previous deductions from less direct evidence.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...