共查询到20条相似文献,搜索用时 15 毫秒
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A Reply to the Comment by Englert, Scully, and Walther. 相似文献
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M. Ould-Rouiss 《The European Physical Journal B - Condensed Matter and Complex Systems》2000,15(2):339-347
Kinematics and dynamics of homogeneous axisymmetric turbulence have been derived with the assumption that the properties of
the turbulence are invariant with respect to rotation about a preferred direction . In particular, the “axisymmetric" equivalent of Karman-Howarth “isotropic" equation is derived using Lindborg's representation
of the two-point correlation tensors of homogeneous axisymmetric turbulence. When the more constraining assumption of isotropy
is made, this equation reduces to the well-known Karman-Howarth equation. There are two interesting limiting forms of the
axisymmetric Karman-Howarth equation: the axisymmetric form of the energy balance equation and the axisymmetric form of the
vorticity balance equation.
Received 1 July 1999 and Received in final form 9 November 1999 相似文献
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Monchaux R Cortet PP Chavanis PH Chiffaudel A Daviaud F Diribarne P Dubrulle B 《Physical review letters》2008,101(17):174502
We experimentally characterize the fluctuations of the nonhomogeneous nonisotropic turbulence in an axisymmetric von Kármán flow. We show that these fluctuations satisfy relations, issued from the Euler equation, which are analogous to classical fluctuation-dissipation relations in statistical mechanics. We use these relations to estimate statistical temperatures of turbulence. 相似文献
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Olga Nánásiová 《International Journal of Theoretical Physics》1993,32(10):1957-1964
Summing of a Boolean algebra and a quantum logic has been defined by P. Pták and studied by, e.g., V. Jani, Z. Rieanová, O. Nánásiová, and C. A. Drossos. It was shown that there is a special case when this structure is a direct product. Drossos has studied the connection between this structure and a Boolean power. In this paper we investigate the conditions when the Pták sum is a free product and when the connection is between the center ofL and the structure of states onBL. 相似文献
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In this paper, the classical von Kármán swirling flow problem due to a rotating disk is modeled and studied for the rate type Maxwell nanofluid together with heat and mass transfer mechanisms. The model under consideration predicts the relaxation time characteristics. The novel aspects of thermophoresis and Brownian motion features due to nanoparticles are investigated by employing an innovative Buongiorno’s model. The analysis further explores the impact of linear Rosseland radiation on heat transfer characteristics. The concept of boundary layer approximations is utilized to formulate the basic governing equations of Maxwell fluid. The dimensionless form of a system of ordinary differential equations is obtained through similarity approach adopted by von Kármán. The system of equations is integrated numerically in domain [0,∞) by using bvp midrich scheme in Maple software. The obtained results intimate that higher rotation raises the radial and angular velocity components. The nano-particles concentration enhances with Brownian motion parameter. Further, the heat transfer rate at the disk surface diminishes with thermophoresis parameter. The achieved numerical computations of velocity profiles, friction coefficient and Nusselt number are matched in limiting cases with previously published literature and an outstanding agreement is observed. 相似文献
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I.IntroductionTomeasurethesound1evelofanundcrwatersoundpulsewithunknownamplitudeisofimportanceinunderwaterapp1ication.Forinstancc,asimu1ationsystemusedtointerfcresomesonarmusthavesuchfunction,whichhastobeabIctomeasurethesoundlcvelatreceivingpointandretransmitasimulatcdsignalwithrequircdsoundlcvelafterpropcrprocessing.Itisdifficultforanorma1peakorthresho1ddetectortocompletethistask.Thereasonforthisisthattherangeofthesignalamp1itudercaches7O-8odBandthereissomedistortionofsignalwaveform,inaddit… 相似文献
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Bogdanovich P. Rudzikas Z. Šadžiuviené S. 《Acta Physica Academiae Scientiarum Hungaricae》1981,51(1-2):109-115
The method of the use of theGáspár potential in theoretical investigations of the energy spectra of atoms and ions in the Hartree—Fock—Pauli approximation is described. The calculations of the energy spectra of a number of multiple-charged ions in the configurations 1s 22s 22p 23s and 1s 22s 22p 23d are presented as the examples and compared with the experimental data available.
相似文献17.
The signatures of the Kelvin–Helmoltz (K–H) and von Kármán (VK) vortices shed from a semicircular cylinder with flaps of length L/d = 0, 1/3, 1, 2, and 3 were investigated using hotwire anemometry. Here, L and d denote the flap length and diameter of the semi-circular cylinder, respectively. Experiments were performed at Reynolds numbers spanning one order of magnitude, Re ∈ [8.4 × 103,?6.7 × 104]. The results highlight the impact of the flow modulation through rigid flaps on the wake characteristics and dominant vortex shedding. The increase of flap length resulted in reduced mean shear in the near-wake, which influenced the onset and coherence of the K-H instability. Indeed, these motions are less likely to be present in the wake of the L/d = 3 case. The flaps also impacted the frequency of the VK shedding; the associated Strouhal number increased from 0.2 to 0.3 for flaps L/d ? 1. Only the cases without with the shortest flaps (L/d = 1/3) followed St = 0.2. There is a distinctive dependence of the fK ? H/fVK on Reynolds number and flap length. This ratio followed the well-known power-law relationship of circular cylinders in the case without flaps. However, the Reynolds number exponent decreased with increased flap length. 相似文献
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