Sat, 26 Jul 2008 07:26:54 BST CiteULike: l-alex's entrainment http://www.citeulike.org/user/l-alex/tag/entrainment CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/l-alex/article/3015770 <i>Physics of Fluids, Vol. 19, No. 7. (2007)</i><br /><br />View This Record in Scopus Small-scale aspects of flows in proximity of the turbulent/nonturbulent interface M Holzner A Liberzon N Nikitin W Kinzelbach A Tsinober Physics of Fluids, Vol. 19, No. 7. (2007) 2008-07-17T20:41:45-00:00 2007 Physics of Fluids 19 7 AIP entrainment experiment interface small-scale http://www.citeulike.org/user/l-alex/article/2750793 <i>Physics of Fluids, Vol. 20, No. 5. (2008)</i> Invariants of the velocity-gradient, rate-of-strain, and rate-of-rotation tensors across the turbulent/nonturbulent interface in jets Carlos da Silva José Pereira Physics of Fluids, Vol. 20, No. 5. (2008) 2008-05-03T21:51:57-00:00 2008 Physics of Fluids 20 5 AIP dns entrainment jet numerical http://www.citeulike.org/user/l-alex/article/1876657 <i>Physics of Fluids, Vol. 21, No. 10. (1978), pp. 1698-1701.</i><br /><br />An experiment was designed to measure the position of a front separating turbulent and nonturbulent fluid as the front moves away from an oscillating grid located near the plane z=0. The theory predicts D (Kt)1/2, where D is the distance of the front from z=0, t=0 is time at which the oscillation begins, and K is a quantity of the dimensions and character of eddy viscosity, called the ”action” of the idealized plane energy source that replaces the grid in the theoretical model. The experimental results support the theory. Physics of Fluids is copyrighted by The American Institute of Physics. doi:10.1063/1.862110 PACS: 47.25.Cg Additional Information Full Text: [ PDF (215 kB) Laboratory study of the growth of a turbulent layer of fluid Stuart Dickinson Robert Long doi:10.1063/1.862110 Physics of Fluids, Vol. 21, No. 10. (1978), pp. 1698-1701. 2007-11-07T07:50:27-00:00 1978 Physics of Fluids 21 10 1698 1701 AIP entrainment oscillating-grid turbulence http://www.citeulike.org/user/l-alex/article/1708314 <i>J. Fluid Mech., Vol. 24 (1966), pp. 89-98.</i> An experimental examination of the large-eddy equilibrium hypothesis IS Gartshore J. Fluid Mech., Vol. 24 (1966), pp. 89-98. 2007-09-29T16:00:19-00:00 1966 J. Fluid Mech. 24 89 98 entrainment http://www.citeulike.org/user/l-alex/article/1021660 <i>Environmental Fluid Mechanics, Vol. 6, No. 5. (October 2006), pp. 407-424.</i> Calculation of Entrainment in Density Jumps Regev Hassid Poreh doi:10.1007/s10652-006-9000-9 Environmental Fluid Mechanics, Vol. 6, No. 5. (October 2006), pp. 407-424. 2007-01-01T16:42:15-00:00 2006 Environmental Fluid Mechanics 1567-7419 6 5 407 424 Springer entrainment http://www.citeulike.org/user/l-alex/article/1395009 <i>Physics of Fluids, Vol. 10, No. 6. (1967), pp. 1349-1349.</i><br /><br />The assumption of self-similarity and the existence of an exact invariant are combined to predict the decay rate of homogeneous turbulence. ©1967 The American Institute of Physics Note on Decay of Homogeneous Turbulence PG Saffman doi:10.1063/1.1762284 Physics of Fluids, Vol. 10, No. 6. (1967), pp. 1349-1349. 2007-06-17T12:14:59-00:00 1967 Physics of Fluids 10 6 1349 1349 AIP entrainment oscillating-grid http://www.citeulike.org/user/l-alex/article/1394862 <i>Fluid Dynamics Research, Vol. 36, No. 1. (January 2005), pp. 23-34.</i><br /><br />An experimental study of orderly flow structures in turbulence with background rotation is presented. Experiments are performed on grid-generated turbulent flows of water filling a rotating tank. Flow velocity fields are visualized using a tracer-particle technique and measured using a laser Doppler velocimeter. Six types of orderly flow structures are found to depend on the Rossby and Reynolds numbers. The effect of the background rotation on the mean circumferential velocity, turbulence intensity and wavenumber spectrum of the flow is investigated. When the Rossby number is small, the variations of the mean velocity and turbulence intensity with depth are kept small, and the deviation of the wavenumber spectrum from the -5/3 law is noticeable. Orderly flow structures in grid-generated turbulence with background rotation Y Sugihara M Migita H Honji Fluid Dynamics Research, Vol. 36, No. 1. (January 2005), pp. 23-34. 2007-06-17T08:33:38-00:00 2005 Fluid Dynamics Research 36 1 23 34 entrainment grid rotation http://www.citeulike.org/user/l-alex/article/1341721 <i>International Journal of Thermal Sciences, Vol. 41, No. 1. (January 2002), pp. 1-16.</i><br /><br />This article reviews the research carried out to characterise the effect of free stream turbulence on heat transfer coefficients at the surface of a plate. In spite of the contradictions which appear at first glance, it seems that the transfer coefficient increases according to the free stream turbulence level either in the laminar boundary layer or in the turbulent boundary layer. The transfer coefficient increases regularly from turbulence level of 5% to 10% obtained with grid-type generators to the higher values of between 20% and 60% generated from jets. However describing the phenomenon using the sole effect of turbulence level leads to a large disparity of experimental results. Analysing the evolution of velocity and near wall temperature profiles under the influence of an increasing free stream turbulence leads to an interpretation which would make it possible to understand the nature of the phenomenon and explain the disparity of experimental results. Effect of high free stream turbulence on heat transfer between plates and air flows: A review of existing experimental results Alain Kondjoyan Frederic Peneau Henri-Claude Boisson International Journal of Thermal Sciences, Vol. 41, No. 1. (January 2002), pp. 1-16. 2007-05-29T20:26:21-00:00 2002 International Journal of Thermal Sciences 41 1 1 16 boundary-layer entrainment heat-transfer http://www.citeulike.org/user/l-alex/article/1282094 <i>(4 May 2007)</i><br /><br />The work reported below is a first of its kind study of the properties of turbulent flow without strong mean shear in a Newtonian fluid in proximity of the turbulent/non-turbulent interface, with emphasis on the small scale aspects. The main tools used are a three-dimensional particle tracking system (3D-PTV) allowing to measure and follow in a Lagrangian manner the field of velocity derivatives and direct numerical simulations (DNS). The comparison of flow properties in the turbulent (A), intermediate (B) and non-turbulent (C) regions in the proximity of the interface allows for direct observation of the key physical processes underlying the entrainment phenomenon. The differences between small scale strain and enstrophy are striking and point to the definite scenario of turbulent entrainment via the viscous forces originating in strain. Small scale aspects of flows in proximity of the turbulent/non-turbulent interface M Holzner A Liberzon N Nikitin W Kinzelbach A Tsinober (4 May 2007) 2007-05-07T17:20:21-00:00 2007 entrainment http://www.citeulike.org/user/l-alex/article/1252039 <i>Inzhenerno-Fizicheskii Zhurnal, Vol. 43, No. 2. (1982), pp. 220-224.</i> Effect of polymer additives on propagation of turbulence front VN Kalashnikov VA Kalinichenko Inzhenerno-Fizicheskii Zhurnal, Vol. 43, No. 2. (1982), pp. 220-224. 2007-04-26T05:20:16-00:00 1982 Inzhenerno-Fizicheskii Zhurnal 43 2 220 224 drag-reduction entrainment grid polymers http://www.citeulike.org/user/l-alex/article/1051602 <i>Fluid Dynamics Research, Vol. 36, No. 2. (February 2005), pp. 75-89.</i><br /><br />Results are described from a series of laboratory experiments in which the effects of a localized two-dimensional region of turbulence on the spatial development of a round, turbulent jet have been investigated. The evolution of the jet has been studied for respective cases with and without background turbulence in the receiving environment. For the former flow configuration, the breakdown of the jet by the presence of background turbulence (generated by an oscillating grid) has been investigated parametrically for a range of values of the source specific momentum flux J0 of the jet and the grid action K. Measurements of the location of the breakdown point of the jet, as detected by (i) a significant local increase in the jet spreading angle and (ii) the simultaneous decrease and increase in the magnitude of the axial and horizontal velocity components, respectively, of the flow field, confirm scaling predictions showing that the jet is destroyed significantly by the background turbulence when the background turbulence intensity is of the same order as the local turbulence intensity of the jet. A laboratory investigation into the influence of a localized region of turbulence on the evolution of a round turbulent jet Yakun Guo Daniela Malcangio Peter Davies Harindra Fernando doi:10.1016/j.fluiddyn.2005.01.001 Fluid Dynamics Research, Vol. 36, No. 2. (February 2005), pp. 75-89. 2007-01-19T12:59:15-00:00 2005 Fluid Dynamics Research 36 2 75 89 entrainment grid jet http://www.citeulike.org/user/l-alex/article/909964 <i>Experiments in Fluids</i> Generalized detection of a turbulent front generated by an oscillating grid Markus Holzner Alexander Liberzon Michele Guala Arkady Tsinober Wolfgang Kinzelbach doi:10.1007/s00348-006-0193-y Experiments in Fluids 2006-10-22T17:42:29-00:00 Experiments in Fluids entrainment http://www.citeulike.org/user/l-alex/article/909836 <i>No. TN-3133, TR-1244. (1954, 1955), pp. 1033-1064.</i> The free-stream boundaries of turbulent flows S Corrsin AL Kistler No. TN-3133, TR-1244. (1954, 1955), pp. 1033-1064. 2006-10-22T17:20:06-00:00 TN-3133, TR-1244 1033 1064 entrainment http://www.citeulike.org/user/l-alex/article/862971 <i>Physics of Fluids, Vol. 8, No. 9. (1996), pp. 2435-2440.</i><br /><br />The purpose of this paper is to present the results of a laboratory experiment dealing with one-dimensional propagation of a turbulent front induced by an oscillating grid in a homogeneous fluid. The symmetrical quadrupolar mode of the flow, induced by the grid elements, was studied in the range KC=4–45, S=1–20 (KC is the Keulegan–Carpenter number, S is the Stokes number). It is shown that the depth H of the turbulent layer increases with time t as Ht1/2. Experimental data for different grid parameters and oscillation amplitudes and frequencies are presented in the nondimensional form h=const 1/2, using nondimensional depth h of the turbulent layer and nondimensional time . A semiempirical model is presented to explain this behavior. This model is based on the properties of a flow induced in a visous fluid by localized forcing of a line force dipole (force doublet). ©1996 American Institute of Physics. Propagation of grid turbulence in homogeneous fluids SI Voropayev HJS Fernando doi:10.1063/1.869028 Physics of Fluids, Vol. 8, No. 9. (1996), pp. 2435-2440. 2006-09-23T10:50:18-00:00 1996 Physics of Fluids 8 9 2435 2440 AIP entrainment http://www.citeulike.org/user/l-alex/article/840843 <i>Physics of Fluids, Vol. 16, No. 12. (2004), pp. 4746-4749.</i><br /><br />An approach is suggested that is useful for studies of the turbulent mixing efficiency, or mixed-fluid volume fraction, based on the dynamics of the interface between pure fluid and mixed fluid. Above the mixing transition, the volume of mixed fluid bounded by this interface is strongly dominated by the large-scale interfacial features. This is examined using high-resolution measurements in jets at Re~20 000. Robustness to resolution effects is found with ~98% of the mixing efficiency captured by coarse graining at ten times lower resolution per dimension. Such reduction in interfacial information has implications for computations, experiments, and physical modeling. ©2004 American Institute of Physics Interfacial-fluid dynamics and the mixing efficiency of turbulent flows Haris Catrakis Roberto Aguirre doi:10.1063/1.1811671 Physics of Fluids, Vol. 16, No. 12. (2004), pp. 4746-4749. 2006-09-12T09:57:22-00:00 2004 Physics of Fluids 16 12 4746 4749 AIP entrainment image-processing mixing scalar http://www.citeulike.org/user/l-alex/article/839664 <i>NACA, Vol. 1244 (1954)</i> Free-stream boundaries of turbulent flows S Corrsin AL Kistler NACA, Vol. 1244 (1954) 2006-09-11T23:10:52-00:00 1954 NACA 1244 NACA entrainment http://www.citeulike.org/user/l-alex/article/790709 <i>J. Fluid Mech., Vol. 51, No. 1. (1972), pp. 97-118.</i> The entrainment interface OM Phillips J. Fluid Mech., Vol. 51, No. 1. (1972), pp. 97-118. 2006-08-09T10:04:58-00:00 1972 J. Fluid Mech. 51 1 97 118 entrainment http://www.citeulike.org/user/l-alex/article/777381 <i>Nature, Vol. 224, No. 20. (1969), pp. 1195-1195.</i> Turbulent diffusion of heat in jets of dilute polymer solutions SA Vlasov VN Kalashnikov Nature, Vol. 224, No. 20. (1969), pp. 1195-1195. 2006-07-28T08:06:11-00:00 1969 Nature 224 20 1195 1195 drag-reduction entrainment polymers http://www.citeulike.org/user/l-alex/article/758133 <i>J. Fluid Mech., Vol. 26 (1966), pp. 689-715.</i> The mechanism of entrainment in free turbulent flows AA Townsend J. Fluid Mech., Vol. 26 (1966), pp. 689-715. 2006-07-13T19:55:52-00:00 1966 J. Fluid Mech. 26 689 715 entrainment http://www.citeulike.org/user/l-alex/article/758108 <i>J. Fluid Mech., Vol. 137 (1983), pp. 307-329.</i><br /><br />This paper is a study of how external turbulence affects an initially turbulence-free region in which there is a mean-velocity gradient dU/dz. Rapid-distortion theory shows how external turbulence induces irrotational fluctuations in the sheared region, which interact with the shear to produce rotational velocity fluctuations and mean Reynolds stresses. These stresses extend into the sheared region over a distance of the order of the integral scale L[infty infinity]. Since the actual front between the initial external turbulence and the shear flow is a randomly contorted surface, the turbulence of a fixed point near the front is intermittent. Intermittency is included in the present analysis by a simple statistical model. Experiments were done in a wind tunnel with the flow divided by a plate extending from upstream to x = 0. Above the plate, turbulence was produced by a grid. Below the plate a low turbulence shear was produced by wire screens. The wake of the plate (x > 0) decayed downstream. Turbulent shear stress was observed to grow from zero to significant values in the interaction region. The magnitude and extent of the observed stress agrees reasonably well with predictions. We conclude that turbulent stresses can be produced by irrotational fluctuations in a region of mean shear, and that this effect can be estimated using rapid-distortion theory. The production of turbulent stress in a shear flow by irrotational fluctuations IS Gartshore PA Durbin JCR Hunt J. Fluid Mech., Vol. 137 (1983), pp. 307-329. 2006-07-13T19:35:11-00:00 1983 J. Fluid Mech. 137 307 329 entrainment http://www.citeulike.org/user/l-alex/article/592056 <i>EiF, Vol. 33 (2002), pp. 873-878.</i><br /><br />identification of entrainment boundary, PIV, PLIF The Turbulent/Non-Turbulent Interface at the Outer Boundary of a Self-Similar Turbulent Jet J Westerweel T Hofmann C Fukushima JCR Hunt doi:10.1007/s00348-002-0489-5 EiF, Vol. 33 (2002), pp. 873-878. 2006-04-20T15:39:53-00:00 2002 EiF 33 873 878 entrainment