Physics of Fluids: All Topics http://scitation.aip.org/ Physics of Fluids: All Topics Instability of a moving liquid sheet in the presence of acoustic forcing http://link.aip.org/link/?PHF/22/022101/1&agg=rss Aditya S. Mulmule, Mahesh S. Tirumkudulu, and K. Ramamurthi<br/> The excitation of thin planar liquid sheets formed by impinging two collinear water jets to acoustic waves was studied at varying frequencies and sound pressure levels (SPLs). Experiments were conducted over a range of liquid velocities that encompassed the stable and flapping regimes of the sheet. ... [Phys. Fluids 22, 022101 (2010)] published Fri Feb 5, 2010. Dynamics and shape instability of thin viscous sheets http://link.aip.org/link/?PHF/22/023601/1&agg=rss Andrey Filippov and Zheming Zheng<br/> An asymptotic theory for predicting the thickness distribution and geometry of the boundaries of a thin nearly planar fluid sheet and analyzing the stability of its shape is developed starting from the balance law for mass and momentum for a continuous medium. The resulting equations comprise a tran ... [Phys. Fluids 22, 023601 (2010)] published Wed Feb 3, 2010. Control of vortical structures on a flapping wing via a sinusoidal leading-edge http://link.aip.org/link/?PHF/22/021701/1&agg=rss C. A. Ozen and D. Rockwell<br/> The flow structure generated by a flapping wing in the form of a plate is fundamentally altered if the leading-edge has a sinusoidal shape. It is possible to attenuate both the positive and negative spanwise flows along the plate surface, as well as the onset and development of large-scale concentra ... [Phys. Fluids 22, 021701 (2010)] published Wed Feb 3, 2010. Nuclear magnetic resonance measurement and lattice-Boltzmann simulation of the nonlocal dispersion tensor http://link.aip.org/link/?PHF/22/027101/1&agg=rss M. W. Hunter, A. N. Jackson, and P. T. Callaghan<br/> The nonlocal dispersion tensor D provides a fundamental description of velocity correlations and displacement information in a dispersive system. It is shown that pulsed gradient spin echo nuclear magnetic resonance can be used to measure this tensor, and we present here the first measurement of D i ... [Phys. Fluids 22, 027101 (2010)] published Mon Feb 1, 2010. Influence of confinement on temporal stability of plane jets and wakes http://link.aip.org/link/?PHF/22/014106/1&agg=rss L. Biancofiore and F. Gallaire<br/> It has been recently shown [M. P. Juniper, The effect of confinement on the stability of two-dimensional shear flows, J. Fluid Mech. 565, 171 (2006)] that the absolute instability of a two-dimensional jet/wake was favored when confined in the normal direction by two flat plates. In this paper, we co ... [Phys. Fluids 22, 014106 (2010)] published Thu Jan 28, 2010. Interaction of weakly compressible isotropic turbulence with planar expansion waves: Flow anisotropy and vorticity alignment http://link.aip.org/link/?PHF/22/015111/1&agg=rss Savvas Xanthos, Minwei Gong, and Yiannis Andreopoulos<br/> Further analysis of the experimental data of the velocity gradient tensor first published by Xanthos et al. [J. Fluid Mech. 584, 301 (2007)] has been carried out and new results are reported here to provide additional insights on the effects of expansion waves interacting with isotropic turbulence. ... [Phys. Fluids 22, 015111 (2010)] published Tue Jan 26, 2010. Temporal large eddy simulations of turbulent viscoelastic drag reduction flows http://link.aip.org/link/?PHF/22/013103/1&agg=rss L. Thais, A. E. Tejada-Martinez, T. B. Gatski, and G. Mompean<br/> We report on temporal large eddy simulations (TLES) of the turbulent channel flow of a dilute polymer solution modeled with the FENE-P (finitely extensible nonlinear elastic in the Peterlin approximation) constitutive equation. The large eddy simulations are based upon an approximate temporal deconv ... [Phys. Fluids 22, 013103 (2010)] published Tue Jan 26, 2010. Effect of channel width on the primary instability of inclined film flow http://link.aip.org/link/?PHF/22/012106/1&agg=rss M. Vlachogiannis, A. Samandas, V. Leontidis, and V. Bontozoglou<br/> A procedure is developed to detect the onset of interfacial instability in inclined film flows (with estimated accuracy better than 5%) and is used to show that the finite width of experimental channels stabilizes the undisturbed liquid film. Deviation from the classical prediction scales inversely ... [Phys. Fluids 22, 012106 (2010)] published Tue Jan 26, 2010. On Young's Paradox, and the attractions of immersed parallel plates http://link.aip.org/link/?PHF/22/017103/1&agg=rss Robert Finn<br/> A seemingly paradoxical prediction for behavior of objects with nonconstant contact angles when dipped into fluids is clarified in a new way. The method is then applied to the problem of determining the attraction (or repulsion) of parallel vertical plates dipped into an infinite liquid bath. A crit ... [Phys. Fluids 22, 017103 (2010)] published Mon Jan 25, 2010. Large eddy simulation study of fully developed wind-turbine array boundary layers http://link.aip.org/link/?PHF/22/015110/1&agg=rss Marc Calaf, Charles Meneveau, and Johan Meyers<br/> It is well known that when wind turbines are deployed in large arrays, their efficiency decreases due to complex interactions among themselves and with the atmospheric boundary layer (ABL). For wind farms whose length exceeds the height of the ABL by over an order of magnitude, a fully developed flo ... [Phys. Fluids 22, 015110 (2010)] published Mon Jan 25, 2010. Ordered microdroplet formations of thin ferrofluid layer breakups http://link.aip.org/link/?PHF/22/014105/1&agg=rss Ching-Yao Chen and C.-S. Li<br/> The ordered breakup pattern of a thin layer of ferrofluid drop subjected to a uniform perpendicular field is experimentally investigated. The results confirm a universal pattern formation containing numerous breaking droplets of a uniform size, which is independent of the initial area of ferrofluid ... [Phys. Fluids 22, 014105 (2010)] published Mon Jan 25, 2010. Simulations and model of the nonlinear RichtmyerMeshkov instability http://link.aip.org/link/?PHF/22/014104/1&agg=rss Guy Dimonte and P. Ramaprabhu<br/> The nonlinear evolution of the RichtmyerMeshkov (RM) instability is investigated using numerical simulations with the FLASH code in two dimensions. The purpose of the simulations is to develop an empirical nonlinear model of the RM instability that is applicable to inertial confinement fusion (ICF) ... [Phys. Fluids 22, 014104 (2010)] published Thu Jan 21, 2010. Theory of breakup of core fluids surrounded by a wetting annulus in sinusoidally constricted capillary channels http://link.aip.org/link/?PHF/22/012105/1&agg=rss Igor A. Beresnev and Wen Deng<br/> Analysis of core-annular dynamics in the presence of base flow for arbitrary fluid viscosities leads to an equation describing the temporal evolution of the fluid/fluid interface. The equation follows from the conservation of mass in the small-slope approximation. Its useful applications occur, for ... [Phys. Fluids 22, 012105 (2010)] published Thu Jan 21, 2010. The effect of viscoelasticity on the stability of a pulmonary airway liquid layer http://link.aip.org/link/?PHF/22/011901/1&agg=rss David Halpern, Hideki Fujioka, and James B. Grotberg<br/> The lungs consist of a network of bifurcating airways that are lined with a thin liquid film. This film is a bilayer consisting of a mucus layer on top of a periciliary fluid layer. Mucus is a non-Newtonian fluid possessing viscoelastic characteristics. Surface tension induces flows within the layer ... [Phys. Fluids 22, 011901 (2010)] published Tue Jan 19, 2010. A volume-based hydrodynamic approach to sound wave propagation in a monatomic gas http://link.aip.org/link/?PHF/22/016103/1&agg=rss S. Kokou Dadzie and Jason M. Reese<br/> We investigate sound wave propagation in a monatomic gas using a volume-based hydrodynamic model. In Dadzie et al. [Physica A 387, 6079 (2008)], a microscopic volume-based kinetic approach was proposed by analyzing molecular spatial distributions; this led to a set of hydrodynamic equations incorpor ... [Phys. Fluids 22, 016103 (2010)] published Fri Jan 15, 2010. Sensitivity analysis of a streamwise corner flow http://link.aip.org/link/?PHF/22/014103/1&agg=rss Frederic Alizard, Jean-Christophe Robinet, and Ulrich Rist<br/> The stability of the flow formed by the intersection of two perpendicular flat plates is revisited through a study of the sensitivity to base-flow variations. After a brief presentation of the asymptotic regime, sensitivity functions underlying corner mode (concentrated close to the intersection) an ... [Phys. Fluids 22, 014103 (2010)] published Fri Jan 15, 2010. A modulated gradient model for large-eddy simulation: Application to a neutral atmospheric boundary layer http://link.aip.org/link/?PHF/22/015109/1&agg=rss Hao Lu and Fernando Porte-Agel<br/> The subgrid-scale (SGS) parametrization represents a critical component of a successful large-eddy simulation (LES). It is known that in LES of high-Reynolds-number atmospheric boundary layer turbulence, standard eddy-viscosity models poorly predict mean shear in the near-wall region and yield erron ... [Phys. Fluids 22, 015109 (2010)] published Fri Jan 15, 2010. Vertical dispersion of light inertial particles in stably stratified turbulence: The influence of the Basset force http://link.aip.org/link/?PHF/22/013301/1&agg=rss M. van Aartrijk and H. J. H. Clercx<br/> The dispersion of light inertial particles [rho/rho=[script O](1)] in statistically stationary stably stratified turbulence is studied by means of direct numerical simulations. The light particle dispersion behavior is found to be comparable to that of heavy particles when displayed as a function of ... [Phys. Fluids 22, 013301 (2010)] published Fri Jan 15, 2010. Three-dimensional vorticity measurements in the wake of a yawed circular cylinder http://link.aip.org/link/?PHF/22/015108/1&agg=rss T. Zhou, H. Wang, S. F. Mohd. Razali, Y. Zhou, and L. Cheng<br/> Using a phase-averaged technique, the dependence of the wake vortical structures on cylinder yaw angle alpha (=0 degrees 45 degrees ) was investigated by measuring all three-velocity and vorticity components simultaneously using an eight-hot wire vorticity probe in the intermediate region (x/d=10) o ... [Phys. Fluids 22, 015108 (2010)] published Fri Jan 15, 2010. Steady free-surface flow at the stern of a ship http://link.aip.org/link/?PHF/22/012104/1&agg=rss Benjamin James Binder<br/> New solutions for steady two-dimensional free-surface flow past a curved plate are considered here. They can be interpreted as approximations to the flow locally at the stern of a ship. Weakly nonlinear solutions are derived analytically and nonlinear solutions are computed by boundary integral equa ... [Phys. Fluids 22, 012104 (2010)] published Fri Jan 15, 2010. Effects of nonuniversal large scales on conditional structure functions in turbulence http://link.aip.org/link/?PHF/22/015107/1&agg=rss Daniel B. Blum, Surendra B. Kunwar, James Johnson, and Greg A. Voth<br/> We report measurements of conditional Eulerian and Lagrangian structure functions in order to assess the effects of nonuniversal properties of the large scales on the small scales in turbulence. We study a 1 x 1 x 1.5 m flow between oscillating grids which produces R=285 while containing regions of ... [Phys. Fluids 22, 015107 (2010)] published Thu Jan 14, 2010. Low-order representations of irregular surface roughness and their impact on a turbulent boundary layer http://link.aip.org/link/?PHF/22/015106/1&agg=rss R. Mejia-Alvarez and K. T. Christensen<br/> The present effort explores the relative impact of various topographical scales present within irregular surface roughness on a turbulent boundary layer under both developing- and developed-flow conditions. Low-order representations of highly irregular surface roughness replicated from a turbine-bla ... [Phys. Fluids 22, 015106 (2010)] published Wed Jan 13, 2010. Vortex formation processes from an oscillating circular cylinder at high KeuleganCarpenter numbers http://link.aip.org/link/?PHF/22/015105/1&agg=rss K. M. Lam, J. C. Hu, and P. Liu<br/> Development of vortex patterns around a circular cylinder oscillating in quiescent water is investigated using time-resolved particle image velocimetry. Experiments are performed at KeuleganCarpenter (KC) numbers between 8 and 36 with Reynolds number kept constant at 2400. Similar to previous studie ... [Phys. Fluids 22, 015105 (2010)] published Wed Jan 13, 2010. Mixing kinematics of moderate Reynolds number flows in a T-channel http://link.aip.org/link/?PHF/22/013601/1&agg=rss Susan Thomas, Tim Ameel, and James Guilkey<br/> An experimental study of water flow in a T-shaped channel with rectangular cross section (20 x 20 mm inlet ID and 20 x 40 mm outlet ID) has been conducted for a Reynolds number Re range based on inlet geometry of Re=56422. Dynamical conditions and T-channel geometry of the current study are applic ... [Phys. Fluids 22, 013601 (2010)] published Tue Jan 12, 2010. Morphological instability of the solid-liquid interface in crystal growth under supercooled liquid film flow and natural convection airflow http://link.aip.org/link/?PHF/22/017102/1&agg=rss Kazuto Ueno and Masoud Farzaneh<br/> Ringlike ripples on the surface of icicles are an example of morphological instability of the ice-water interface during ice growth under supercooled water film flow. The surface of icicles is typically covered with ripples of about 1 cm in wavelength, and the wavelength appears to be almost indepen ... [Phys. Fluids 22, 017102 (2010)] published Mon Jan 11, 2010. Direct numerical simulation of a mixing layer downstream a thick splitter plate http://link.aip.org/link/?PHF/22/015104/1&agg=rss Sylvain Laizet, Sylvain Lardeau, and Eric Lamballais<br/> In this numerical study, the flow obtained behind a trailing edge separating two streams of different velocities is studied by means of direct numerical simulation. The main originality of this work is that the splitter plate itself is included in the computational domain using an immersed boundary ... [Phys. Fluids 22, 015104 (2010)] published Mon Jan 11, 2010. Turbulent drag reduction via a transverse wave traveling along streamwise direction induced by Lorentz force http://link.aip.org/link/?PHF/22/015103/1&agg=rss Leping Huang, Baochun Fan, and Gang Dong<br/> Lorentz force can be used to induce motion in the electrically conducting fluids which might then lead to turbulence suppression and drag reduction. In this paper, drag reduction in turbulent channel flow via a transverse wave traveling along streamwise direction induced by Lorentz force is investig ... [Phys. Fluids 22, 015103 (2010)] published Mon Jan 11, 2010. Magnetic field effect on the cooling of a low-Pr fluid in a vertical cylinder http://link.aip.org/link/?PHF/22/017101/1&agg=rss I. E. Sarris, A. I. Iatridis, C. D. Dritselis, and N. S. Vlachos<br/> Results of direct numerical simulations are presented for the transient and turbulent natural convection cooling of an initially isothermal quiescent liquid metal placed in a vertical cylinder in the presence of a vertical magnetic field. The electrically conductive low-Prandtl number fluid is put t ... [Phys. Fluids 22, 017101 (2010)] published Mon Jan 11, 2010. Evolution and lifetimes of flow topology in a turbulent boundary layer http://link.aip.org/link/?PHF/22/015102/1&agg=rss G. E. Elsinga and I. Marusic<br/> The average rates of change in the invariants of the velocity gradient tensor (Q and R) have been determined experimentally in the outer layer of a turbulent boundary layer as a function of the invariants themselves. Subsequent integration yields trajectories in the QR plane describing the average e ... [Phys. Fluids 22, 015102 (2010)] published Mon Jan 11, 2010.