POF: Turbulent Flows

Decaying versus stationary turbulence in particle-laden isotropic turbulence: Turbulence modulation mechanism

Abouelmagd H. Abdelsamie and Changhoon Lee
The objective of the current paper is to clarify the physical distinction between turbulence modulations by laden particles in decaying isotropic turbulence and stationary isotropic turbulence. Direct numerical simulations of stationary and decaying isotropic turbulence were carried out using 128 gr ... [Phys. Fluids 24, 015106 (2012)] published Tue Jan 31, 2012.

Spectral approach to finite Reynolds number effects on Kolmogorov's 4/5 law in isotropic turbulence

J. Tchoufag, P. Sagaut, and C. Cambon
The Kolmogorov's 4/5 law is often considered as the sole exact relationship of inertial range statistics. Its asymptotic character, however, has been evidenced, investigating the finite Reynolds number (FRN) effect for the third-order structure function S(r) (e.g., for longitudinal velocity incremen ... [Phys. Fluids 24, 015107 (2012)] published Tue Jan 31, 2012.

Wall-modeling in large eddy simulation: Length scales, grid resolution, and accuracy

Soshi Kawai and Johan Larsson
This paper addresses one of the most persistent errors in wall-modeled large eddy simulation: the inevitable presence of numerical and subgrid modeling errors in the first few grid points off the wall, which leads to the so-called log-layer mismatch with its associated 10-15% error in the predicted ... [Phys. Fluids 24, 015105 (2012)] published Tue Jan 31, 2012.

Reynolds number effect on the velocity increment skewness in isotropic turbulence

Wouter J. T. Bos, Laurent Chevillard, Julian F. Scott, and Robert Rubinstein
Second and third order longitudinal structure functions and wavenumber spectra of isotropic turbulence are computed using the eddy-damped quasi-normal Markovian model (EDQNM) and compared to results of the multifractal formalism. It is shown that both the multifractal model and EDQNM give power-law ... [Phys. Fluids 24, 015108 (2012)] published Tue Jan 31, 2012.

Flow and mixing characteristics of an elevated pulsating transverse jet

Rong F. Huang and Ching M. Hsu
Flow-evolution processes as well as the penetration, spread, and dispersion characteristics of elevated pulsating transverse jets were studied experimentally in a wind tunnel. Jet pulsations were induced by means of acoustic excitation. Streak pictures of the smoke-flow patterns, illuminated by a la ... [Phys. Fluids 24, 015104 (2012)] published Fri Jan 27, 2012.

A dynamic hybrid Reynolds-averaged Navier StokesLarge eddy simulation modeling framework

S. Bhushan and D. K. Walters
A dynamic framework for hybrid Reynolds-averaged Navier-Stokes (RANS)large eddy simulation (LES) modeling is proposed, wherein the RANS-to-LES transition parameter is adjusted to maintain continuity in turbulence production. The model is applied for temporally developing plane channel flow at varyin ... [Phys. Fluids 24, 015103 (2012)] published Thu Jan 26, 2012.

Anisotropic dynamics and sub-grid energy transfer in wall-turbulence

A. Cimarelli and E. De Angelis
Purpose of the present work is the analysis of the generalized Kolmogorov equation applied to the direct numerical simulation data of a turbulent channel flow. The multi-dimensional description of the anisotropic behavior of turbulent energy production, transport, and dissipation is shown to be rele ... [Phys. Fluids 24, 015102 (2012)] published Thu Jan 26, 2012.

Reynolds number effects on scale energy balance in wall turbulence

Neelakantan Saikrishnan, Elisabetta De Angelis, Ellen K. Longmire, Ivan Marusic, Carlo M. Casciola et al.
The scale energy budget utilizes a modified version of the classical Kolmogorov equation of wall turbulence to develop an evolution equation for the second order structure function [R. J. Hill, Exact second-order structure-function relationships, J. Fluid Mech. 468, 317 (2002)]. This methodology all ... [Phys. Fluids 24, 015101 (2012)] published Tue Jan 17, 2012.

Interactions between turbulence and flames in premixed reacting flows

Peter E. Hamlington, Alexei Y. Poludnenko, and Elaine S. Oran
The interactions between turbulence and flames in premixed reacting flows are studied for a broad range of turbulence intensities by analyzing scalar (reactant mass-fraction) gradient, vorticity, and strain rate fields. The analysis is based on fully compressible, three-dimensional numerical simulat ... [Phys. Fluids 23, 125111 (2011)] published Fri Dec 30, 2011.

Statistical mechanics and large-scale velocity fluctuations of turbulence

Hideaki Mouri, Akihiro Hori, Yoshihide Kawashima, and Kosuke Hashimoto
Turbulence exhibits significant velocity fluctuations even if the scale is much larger than the scale of the energy supply. Since any spatial correlation is negligible, these large-scale fluctuations have many degrees of freedom and are thereby analogous to thermal fluctuations studied in the statis ... [Phys. Fluids 23, 125110 (2011)] published Tue Dec 20, 2011.

Is the Smagorinsky coefficient sensitive to uncertainty in the form of the energy spectrum?

M. Meldi, D. Lucor, and P. Sagaut
We investigate the influence of uncertainties in the shape of the energy spectrum over the Smagorinsky [General circulation experiments with the primitive equations. I: The basic experiment, Mon. Weather Rev. 91(3), 99 (1963)] subgrid scale model constant C: the analysis is carried out by a stochast ... [Phys. Fluids 23, 125109 (2011)] published Tue Dec 20, 2011.

Direct numerical simulation of a high-Froude-number turbulent open-channel flow

Yoshinobu Yamamoto and Tomoaki Kunugi
In this study, we successfully conducted a direct numerical simulation of a high-Fr turbulent open-channel flow at a Froude number of 1.8 and a Reynolds number of 2325 based on bulk velocity, gravitational acceleration, water depth, and kinetic viscosity, using the multi-interface advection and reco ... [Phys. Fluids 23, 125108 (2011)] published Fri Dec 16, 2011.

Effect of flow-geometry on turbulence-scalar interaction in premixed flames

Y. Minamoto, N. Fukushima, M. Tanahashi, T. Miyauchi, T. D. Dunstan et al.
Turbulent combustion of stoichiometric hydrogen-air mixture is simulated using direct numerical simulation methodology, employing complex chemical kinetics. Two flame configurations, freely propagating and V-flames stabilized behind a hot rod, are simulated. The results are analyzed to study the inf ... [Phys. Fluids 23, 125107 (2011)] published Tue Dec 13, 2011.

Numerical investigations of turbulent flow characteristics in helically finned pipe

F. Nygard and H. I. Andersson
A helical fin in a circular pipe is a means to generate swirling flow and the swirling motion will in turn modulate the turbulence field. This paper reports on a direct numerical simulation aimed to explore such flow phenomena. The full Navier-Stokes equations expressed in a cylindrical coordinate s ... [Phys. Fluids 23, 125106 (2011)] published Fri Dec 9, 2011.

Relaminarisation of Re = 100 channel flow with globally stabilising linear feedback control

A. S. Sharma, J. F. Morrison, B. J. McKeon, D. J. N. Limebeer, W. H. Koberg et al.
The problems of nonlinearity and high dimension have so far prevented a complete solution of the control of turbulent flow. Addressing the problem of nonlinearity, we propose a flow control strategy which ensures that the energy of any perturbation to the target profile decays monotonically. The con ... [Phys. Fluids 23, 125105 (2011)] published Wed Dec 7, 2011.

Horizontal structures of velocity and temperature boundary layers in two-dimensional numerical turbulent Rayleigh-Benard convection

Quan Zhou (周全), Kazuyasu Sugiyama, Richard J. A. M. Stevens, Siegfried Grossmann, Detlef Lohse et al.
We investigate the structures of the near-plate velocity and temperature profiles at different horizontal positions along the conducting bottom (and top) plate of a Rayleigh-Benard convection cell, using two-dimensional (2D) numerical data obtained at the Rayleigh number Ra = 10 and the Prandtl numb ... [Phys. Fluids 23, 125104 (2011)] published Wed Dec 7, 2011.

Scaling of maximum probability density functions of velocity and temperature increments in turbulent systems

Y. X. Huang (黄永祥), F. G. Schmitt, Q. Zhou (周全), X. Qiu (邱翔), X. D. Shang (尚晓东) et al.
In this paper, we introduce a new way to estimate the scaling parameter of a self-similar process by considering the maximum probability density function (pdf) of its increments. We prove this for H-self-similar processes in general and experimentally investigate it for turbulent velocity and temper ... [Phys. Fluids 23, 125101 (2011)] published Mon Dec 5, 2011.

ODTLES simulations of wall-bounded flows

Esteban D. Gonzalez-Juez, Rodney C. Schmidt, and Alan R. Kerstein
ODTLES is a novel multi-scale model for 3D turbulent flow based on the one-dimensional-turbulence model of Kerstein [One-dimensional turbulence: Model formulation and application to homogeneous turbulence, shear flows, and buoyant stratified flows, J. Fluid Mech. 392, 277 (1999)]. Its key distinctio ... [Phys. Fluids 23, 125102 (2011)] published Mon Dec 5, 2011.

Effect of shocklets on the velocity gradients in highly compressible isotropic turbulence

Jianchun Wang, Yipeng Shi, Lian-Ping Wang, Zuoli Xiao, Xiantu He et al.
The effect of randomly generated shocklets on velocity gradients in a three-dimensional compressible isotropic turbulence was systematically studied. The forced flows obtained from high-resolution simulations had a turbulent Mach number of 1.0 and a Taylor microscale Reynolds number around 180. The ... [Phys. Fluids 23, 125103 (2011)] published Mon Dec 5, 2011.

Evolution of a confined turbulent jet in a long cylindrical cavity: Homogeneous fluids

S. I. Voropayev, X. Sanchez, C. Nath, S. Webb, and H. J. S. Fernando
The flow induced in a long cylinder by an axially discharging round turbulent jet was investigated experimentally with applications to crude oil storage in the U.S. strategic petroleum reserves (SPR). It was found that the flow does not reach a true steady state, but vacillates periodically. Digital ... [Phys. Fluids 23, 115106 (2011)] published Tue Nov 29, 2011.

Direction of scalar transport in turbulent channel flow

Chiranth Srinivasan and Dimitrios V. Papavassiliou
The concept of reverse diffusion, introduced by Corrsin to describe the motion of particles as they move towards a location in the flow field, is fundamental to the understanding of mixing. In this work, direct numerical simulations in conjunction with the tracking of scalar markers are utilized in ... [Phys. Fluids 23, 115105 (2011)] published Fri Nov 11, 2011.