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Laminar to turbulent transitions of pipe flows by resonances of natural frequencies of components of test sections J. Turbul. (IF 1.9) Pub Date : 2024-02-22 F. Durst, G. Biswas, K. Haddad
This investigation analyses special papers and doctoral theses that treat transitions of pipe flows as a resonance phenomenon of wave frequencies. These frequencies are natural frequencies of pipe ...
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Variational calculus in hybrid turbulence transport models with passive scalar J. Turbul. (IF 1.9) Pub Date : 2024-01-25 Bruno Chaouat, Roland Schiestel
Non-zonal methods of hybrid Reynolds Averaged Navier–Stokes (RANS) equations-Large Eddy Simulation (LES) with subfilter transport equations enable to simulate turbulent flows out of spectral equili...
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Quantifying instantaneous flow reversal of tracer particles in subsonic, transonic and supersonic flows past a circular cylinder J. Turbul. (IF 1.9) Pub Date : 2024-01-17 Huiying Zhang, James M. Wallace, Xiaohua Wu
Tracer pathline statistics have rarely, if at all, been used in the investigation of compressible subsonic, transonic and supersonic flows past a circular cylinder. Here, we report pathline histogr...
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Evaluating anisotropic minimum dissipation, sigma and modulated gradient subgrid-scale models in large-eddy simulation of compressible mixing layers J. Turbul. (IF 1.9) Pub Date : 2024-01-17 Peddamma Vishwaja, Niranjan S. Ghaisas
We evaluate three subgrid-scale (SGS) models in large eddy simulations (LES) of compressible mixing layers up to convective Mach number ( Mc) 2.0. The initial momentum-thickness based Reynolds numb...
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Circulation in turbulent flow through a contraction J. Turbul. (IF 1.9) Pub Date : 2024-01-17 Vivek Mugundhan, Sigurdur T. Thoroddsen
We study experimentally the statistical properties and evolution of circulation in a turbulent flow passing through a smooth 2-D contraction. The turbulence is generated with active grids to reach ...
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Advanced detached-eddy simulation of the MD 30P-30N three-element airfoil J. Turbul. (IF 1.9) Pub Date : 2024-01-17 Mikhail Shur, Mikhail Strelets, Philippe Spalart, Andrey Travin
An experimental version in the Detached-Eddy Simulation (DES) family (called Advanced DES or ADES) is introduced and tested on a geometry that is fairly complex but two-dimensional. The essential c...
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Fractional and tempered fractional models for Reynolds-averaged Navier–Stokes equations J. Turbul. (IF 1.9) Pub Date : 2024-01-17 Pavan Pranjivan Mehta
Turbulence is a non-local phenomenon and has multiple-scales. Non-locality can be addressed either implicitly or explicitly. Implicitly, by subsequent resolution of all spatio-temporal scales. Howe...
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Exciting turbulence in an elongated domain J. Turbul. (IF 1.9) Pub Date : 2024-01-08 Tong Wu, Le Fang, Joachim Peinke, Wouter J. T. Bos
Motivated by recent experimental results in grid turbulence with very long streamwise velocity correlations, we consider numerical simulations of turbulence in a domain that is elongated in one dir...
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Wall heat flux in supersonic turbulent expansion flow with shock impingement J. Turbul. (IF 1.9) Pub Date : 2023-10-13 Fulin Tong, Junyi Duan, Xianxu Yuan, Xinliang Li
We perform direct numerical simulations to investigate the characteristics of wall heat flux (WHF) in the interaction of an oblique shock wave at an angle of 33.2° and free-stream Mach number M∞ = ...
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A surrogate non-intrusive reduced order model of quasi-geostrophic turbulence dynamics based on a combination of LSTM and different approaches of DMD J. Turbul. (IF 1.9) Pub Date : 2023-10-13 Mina Golzar, Mohammad Kazem Moayyedi, Faranak Fotouhi
Mathematical modeling is applied to study phenomena and system behavior.In various engineering fields, many physical phenomena are illustrated using a set of differential equations.In many real-wor...
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Evolution of turbulent mixing driven by implosion in spherical geometry J. Turbul. (IF 1.9) Pub Date : 2023-07-18 Tao Wang, Min Zhong, Bing Wang, Ping Li, Jingsong Bai
The interface instability and turbulent mixing of perturbed multi-modes Air/SF6 interface driven by implosion in spherical geometry are numerically investigated. The results show the complex evolvi...
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Toward the use of LES for industrial complex geometries. Part II: Reduce the time-to-solution by using a linearised implicit time advancement J. Turbul. (IF 1.9) Pub Date : 2023-06-19 Thomas Berthelon, Guillaume Sahut, Julien Leparoux, Guillaume Balarac, Ghislain Lartigue, Manuel Bernard, Vincent Moureau, Olivier Métais
The strong increase in computational power observed during the last few years has allowed to use Large Eddy Simulation (LES) for industrial configurations. Nevertheless, the time-to-solution is still too large for a daily use in the design phases. The objective of this work is to develop a new time integration method to reduce the time-to-solution of LES of incompressible flows by allowing the use
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The myth of URANS J. Turbul. (IF 1.9) Pub Date : 2023-06-19 Daniel M. Israel
ABSTRACT Since the 1990s, RANS practitioners have observed spontaneous unsteadiness in RANS simulations. Some have suggested deliberately using this as a method of resolving large turbulent structures. However, to date, no one has produced a theoretical justification for this unsteady RANS (URANS) approach. Here, we extend the dynamical system fixed point analysis to create a theoretical model for
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Mesh and model requirements for capturing deep-stall aerodynamics in low-Mach-number flows J. Turbul. (IF 1.9) Pub Date : 2023-06-14 Shreyas Bidadi, Ganesh Vijayakumar, Ashesh Sharma, Michael A. Sprague
The paper presents a comprehensive computational fluid dynamics investigation of the effects of grid resolution and turbulence-model choice for capturing the unsteady three-dimensional aerodynamic performance of NACA 0012 and 0021 airfoils, with specific focus on the deep-stall regime. At high angles of attack (α), wind turbine blades routinely experience vortex-induced vibrations, which can cause
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Effects of groove distributions on supersonic turbulent channel flows J. Turbul. (IF 1.9) Pub Date : 2023-06-12 YaLu Fu, QingQing Zhou, Ming Yu, HongMin Su, QiLong Guo, XianXu Yuan
This paper investigates the influences of the distribution of the grooves on the wall on the turbulent statistics, transport of turbulent kinetic energy, and flow structures in supersonic turbulent channel flows at the bulk Mach number of 3.0 by performing direct numerical simulations. It is found that the existence of the grooves leads to the enhancement of the turbulent kinetic energy close to the
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Letter from the editors J. Turbul. (IF 1.9) Pub Date : 2023-06-08
Published in Journal of Turbulence (Vol. 24, No. 6-7, 2023)
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Toward the use of LES for industrial complex geometries. Part I: automatic mesh definition J. Turbul. (IF 1.9) Pub Date : 2023-05-28 A. Grenouilloux, J. Leparoux, V. Moureau, G. Balarac, T. Berthelon, R. Mercier, M. Bernard, P. Bénard, G. Lartigue, O. Métais
With the constant increase of computational power for the past years, Computational Fluid Dynamics (CFD) has become an essential part of the design in complex industrial processes. In this context, among the scale resolving numerical methods, Large-Eddy Simulation (LES) has become a valuable tool for the simulation of complex unsteady flows. To generalise the industrial use of LES, two main limitations
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Physical/numerical duality of explicit/implicit subgrid-scale modelling J. Turbul. (IF 1.9) Pub Date : 2023-05-25 R. Vicente Cruz, E. Lamballais
The development of implicit approaches has prompted debate on the actual usefulness of any explicit subgrid-scale modelling in large-eddy simulation. This question is addressed here by considering two generic turbulent flows: (i) the Taylor-Green vortex problem; (ii) the pipe flow. For both flow configurations, implicit modelling is found to overtake the very popular Smagorinsky model. To understand
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Influence of streamwise and spanwise wall magnet arrays on near-wall MHD turbulence J. Turbul. (IF 1.9) Pub Date : 2023-04-20 Amandine Capogna, Olivier Doche, Jonathan Schillings, Laurent Davoust, Sedat Tardu
The effect of a permanent, localised and non-uniform magnetic field on the near-wall turbulence in a fully developed channel flow is analysed through direct numerical simulations. The magnetic field distribution is obtained by an arrangement of magnets placed on the upper and lower channel walls, producing preferentially either a streamwise (i.e. in the main flow direction) or a spanwise magnetic field
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Boundary layer flow over a bump and the three-dimensional law of the wall J. Turbul. (IF 1.9) Pub Date : 2023-04-17 Julie E. Duetsch-Patel, Aldo Gargiulo, Aurélien Borgoltz, Christopher J. Roy, William J. Devenport, K. Todd Lowe
Many turbulence theories in use today are based on two-dimensional equilibrium flows and have limitations when applied to three-dimensional flows. A three-dimensional law of the wall would help to improve simulation fidelity, but while several versions have been proposed, none have been widely accepted. In this study, the three-dimensional attached boundary layer flow over the windward side of the
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Correction J. Turbul. (IF 1.9) Pub Date : 2023-04-13
Published in Journal of Turbulence (Ahead of Print, 2023)
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Special Issue on the “Numerical Simulation of Rough-Wall Flows” J. Turbul. (IF 1.9) Pub Date : 2023-03-24
Published in Journal of Turbulence (Vol. 24, No. 1-2, 2023)
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An EDQNM study of the dissipation rate in isotropic non-equilibrium turbulence J. Turbul. (IF 1.9) Pub Date : 2023-03-16 Le Fang, Wouter J.T. Bos
The energy cascade from large to small scales is a robust feature of three-dimensional turbulence. In statistically steady turbulence, the average dissipation is in equilibrium with the energy injected in the system. A global quantity measuring the deviations from such a flux equilibrium is the normalised dissipation rate CϵCϵ , corresponding to the viscous dissipation, normalised by quantities associated
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Large eddy simulations of the turbulent channel flow over dimpled surfaces J. Turbul. (IF 1.9) Pub Date : 2023-03-07 Yasin Kaan İlter, Aras Çetinkaya, Uğur Oral Ünal
Reducing skin friction has a key role in the efficiency of rail, highway, and airway transport vehicles or naval systems such as ships and underwater vehicles. In recent years, there is a growing interest in investigating turbulent drag-reducing capabilities of dimpled surfaces, which have great potential as a passive solution, while there still exists highly conflicting views and drag reduction rates
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Experimental study of two side-by-side decaying grid turbulent fields at different mean velocities J. Turbul. (IF 1.9) Pub Date : 2023-02-21 MD Kamruzzaman, Lyazid Djenidi, R.A. Antonia
A Hot-wire anemometry experiment is conducted to investigate how two turbulent fields decaying with different mean velocities interact at their interface. A grid with different mesh sizes and solidities on either side of the grid centerline is used to generate two turbulent fields. It is found that the resulting turbulent shear layer created at the interface of the two fields evolves in a self-preserving
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The effect of Prandtl number on decaying stratified turbulence J. Turbul. (IF 1.9) Pub Date : 2023-02-15 James J. Riley, Miles M. P. Couchman, Stephen M. de Bruyn Kops
The effects of the variation in the Prandtl number on turbulence in a stably-stratified fluid is investigated by direct numerical simulation. The results of simulations are presented of the homogeneous decay of turbulence for a given initial Froude number and three different initial Reynolds numbers of increasing values. For each of these cases results for two different Prandtl numbers, 1 and 7, are
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Effect of high skewness and kurtosis on turbulent channel flow over irregular rough walls J. Turbul. (IF 1.9) Pub Date : 2023-02-12 A. Busse, T. O. Jelly
The skewness of the roughness height distribution is one of the key topographical parameters that govern roughness effects on wall-bounded turbulence. In this paper mathematical bounds for realisable values of skewness and kurtosis are discussed in the context of irregular multi-scale rough surfaces, which are representative of typical forms of engineering roughness. The properties of a set of irregular
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Modeling rough walls from surface topography to double averaged Navier-Stokes computation J. Turbul. (IF 1.9) Pub Date : 2023-02-03 F. Chedevergne
The discrete element method was recently revisited using a double averaged Navier-Stokes formulation [Chedevergne F. A double-averaged navier-stokes k−ω turbulence model for wall flows over rough surfaces with heat transfer. J Turbul. 2021 Sep;22(11):713–734. doi:10.1080/14685248.2021.1973014] and a new closure relation for the drag coefficient [Chedevergne F, Forooghi P. On the importance of the drag
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An improved method for coherent structure identification based on mutual K-nearest neighbors J. Turbul. (IF 1.9) Pub Date : 2022-12-20 Zeming Wei, Jiazhong Zhang, Ruidong Jia, Jingsheng Gao
ABSTRACT The clustering algorithm based on mutual K-nearest neighbors (MKNN) is presented to identify coherent structures in complicated fluid flows, in order to analyze the mass mixing and transport. First, both trajectory similarity and spatial proximity are used to describe and measure the coherence between particles. These two identification criteria are frame-invariant since they are derived from
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DNS predictions of NOx production in developing turbulent mixing layers with non-premixed hydrogen–air combustion J. Turbul. (IF 1.9) Pub Date : 2022-12-12 Takashi Ohta, Ryota Hirata, Yasuyuki Sakai
ABSTRACT Direct numerical simulations of three-dimensional compressible mixing layers with non-premixed hydrogen–air combustion were performed using a detailed chemical reaction mechanism with NOx production. Flow fields with three types of initial disturbances were simulated to investigate the relationship between developing vortical structures and NOx formation. The amounts of NO and NO2 produced
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High-enthalpy effects on turbulent coherent structures over a curved compression corner J. Turbul. (IF 1.9) Pub Date : 2022-12-10 Dong Sun, Qilong Guo, Xianxu Yuan, Chen Li, Pengxin Liu
ABSTRACT Direct numerical simulation (DNS) is performed to study high-enthalpy effects on a turbulent boundary layer (TBL) over a curved compression corner. The post-shock flow state behind a wedge flying at Mach 20 and at an altitude of 30 km are chosen for the present simulation. The post-shock temperature is 3400 K, which is high enough to trigger chemical non-equilibrium of the air. A low-enthalpy
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A systematic study of a droplet breakup process in decaying homogeneous isotropic turbulence using a mesoscopic simulation approach J. Turbul. (IF 1.9) Pub Date : 2022-11-20 Jun Lai, Tao Chen, Shengqi Zhang, Zuoli Xiao, Shiyi Chen, Lian-Ping Wang
ABSTRACT The breakup of a spherical droplet in a decaying homogeneous isotropic turbulence is studied by solving the Cahn–Hilliard–Navier–Stokes equations. This flow provides a great opportunity to study the interactions of turbulent kinetic energy and interfacial free energy and their effects on the breakup dynamics. Three distinct stages of droplet evolution, namely, the deformation stage, the breakup
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Influence of turbulent structure on the heat transfer of Rayleigh–Bénard convection with triangular roughness element J. Turbul. (IF 1.9) Pub Date : 2022-11-15 Yuxian Xia, Xiang Qiu, Yuehong Qian
ABSTRACT There is a widely accepted conclusion that the wall roughness do not always enhance the heat transport of the turbulent thermal convection. In this paper, the heat transfer efficiency is statistically investigated from the perspective of turbulent structure. The effect of turbulent structure on the heat transfer of Rayleigh–Bénard convection with triangular rough element on the top and bottom
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Reflections on roughness modelling in turbulent flow J. Turbul. (IF 1.9) Pub Date : 2022-10-23 Paul A. Durbin
The general topic of practical modelling of roughness in turbulent flow is discussed. Double averaging is a useful framework, but most models cannot be construed as term-by-term closures to the double averaged equations. Double averaging justifies a drag representation. Drag models are effective for both Reynolds averaged and eddy resolving simulation. Boundary condition models are primarily viable
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Detailed evaluation of a heat exchanger in terms of effectiveness and second law J. Turbul. (IF 1.9) Pub Date : 2022-10-14 Emre Turgut, Uğurcan Yardımcı
In this study, experiments were conducted to investigate the effects of semicircular strip turbulators placed in the inner tube of a concentric heat exchanger on its exergy loss rate (E*) and effectiveness (e). The Reynolds number (Re), pitch (p), diameter (d), thickness (t) and arrangement style (a) were the design parameters for the study. The changes in these parameters had significant effects on
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Effects of form-induced velocity in rough-wall turbulent channel flows J. Turbul. (IF 1.9) Pub Date : 2022-10-11 S. C. Mangavelli, J. Yuan
Wall roughness induces form-induced (or dispersive) velocity and pressure perturbations inside the roughness sublayer of a wall-bounded turbulent flow. This work discusses the role played by the form-induced velocity in influencing turbulence statistics and structure, using existing direct numerical simulation data of transient half channels in response to an impulse acceleration (Mangavelli et al
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Effect of slip length on flow dynamics and heat transport in two-dimensional Rayleigh–Bénard convection J. Turbul. (IF 1.9) Pub Date : 2022-09-30 Maojing Huang, Xiaozhou He
We report a direct numerical simulation (DNS) study of the heat transport and temperature profiles of the plume ejecting and impacting regions in the two-dimensional turbulent Rayleigh–Bénard (RB) convection with slippery plates and horizontally periodic boundary conditions. The numerical study is conducted in the parameter range of Rayleigh number Ra from 107 to 109 and the slip length b from 0 (NS)
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Drag reduction using velocity control in Taylor–Couette flows J. Turbul. (IF 1.9) Pub Date : 2022-08-06 Obaidullah Khawar, M. F. Baig, Sanjeev Sanghi
Direct numerical simulation of Taylor–Couette flow subject to opposition control is investigated at Reynolds number (Re) of 3000. The idea is to impose exact opposite velocities of the detection plane at the walls to counteract near-wall stream-wise vortices. In this study, various velocity control strategies, namely wall-normal, axial, combined and blowing only, have been investigated from the viewpoint
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Drag reduction by a superhydrophobic surface with longitudinal grooves: the effects of the rib surface curvature J. Turbul. (IF 1.9) Pub Date : 2022-07-14 Jie Yao, C.J. Teo
We have investigated the effects of rib surface curvature of a superhydrophobic wall in both laminar and turbulent channel flows. Direct numerical simulation is performed for laminar flows and large eddy simulation is performed for turbulent flows. The parametric study shows that a convex rib surface leads to a lower flow ratethan a flat rib for all Reynolds numbers. A concave rib surface firstly increases
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Questions on the effects of roughness and its analysis in non-equilibrium flows J. Turbul. (IF 1.9) Pub Date : 2022-07-08 Ralph J. Volino, William J. Devenport, Ugo Piomelli
The prediction of turbulent flows over rough surfaces is important for many applications in engineering and in the natural sciences. Since the resolution of the roughness requires significant computational resources, most modelling approaches rely on the related concepts of ‘equivalent sand-grain roughness’ and ‘wall similarity’. While the validity of these concepts is well established for zero-pressure-gradient
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In memoriam, Marcel Lesieur (1945-2022) J. Turbul. (IF 1.9) Pub Date : 2022-07-06 Ugo Piomelli, Olivier Métais
Published in Journal of Turbulence (Vol. 23, No. 7, 2022)
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Turbulence modulation by finite-size particles of different diameters and particle–fluid density ratios in homogeneous isotropic turbulence J. Turbul. (IF 1.9) Pub Date : 2022-07-06 Jie Shen, Cheng Peng, Jianzhao Wu, Kai Leong Chong, Zhiming Lu, Lian-Ping Wang
In this paper, the influence of particle-fluid density ratio and particle diameter on the turbulence modulation by finite-size particles in forced homogeneous isotropic turbulence is investigated. Results show that the presence of finite-size particles always attenuate the turbulence, and the attenuation is larger for particles with larger density when the particle diameter is fixed. But the attenuation
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Laminar-to-Turbulent Transition of Pipe Flows Triggered by Wall-Mounted, Ring-Type Obstacles J. Turbul. (IF 1.9) Pub Date : 2022-06-29 Franz Durst, Michael Breuer, Bülent Ünsal, Kais Haddad
The literature stresses the inherent stability of laminar pipe flows with parabolic velocity profiles and this paper refers to the relevant publications summarizing this work. To cause such flows to turn into their turbulent state requires laminar pipe flows to be triggered externally. Ring-type, wall-mounted obstacles can be used for this purpose, and investigations in this area are of particular
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Non-isothermal flow past a heated circular cylinder in subcritical regime: a numerical investigation based on large-eddy simulation J. Turbul. (IF 1.9) Pub Date : 2022-06-06 Geng Tian, Zuoli Xiao
Compressible flow past a heated circular cylinder at subcritical Reynolds number of 3900 is numerically investigated by using the large-eddy simulation method. Rigorous validations of the numerical model are carefully performed under isothermal conditions on the basis of available experimental data. The calculated mean flow and Reynolds stresses show good agreement with the published experimental data
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Turbulence characteristics in a weir-orifice-slot combined fishway with an identical layout J. Turbul. (IF 1.9) Pub Date : 2022-05-31 Zhiyong Dong, Jianli Tong, Zhou Huang
A combined fishway containing notched weir, central orifice and vertical slot with an identical layout was designed, and its turbulence characteristics were experimentally studied. An acoustic Doppler velocimetry (ADV) was used to measure three-dimensional velocity. Flow regime, average velocity, turbulence intensity, Reynolds stress, power frequency-spectrum, correlation function, turbulence scale
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Convection of multi-scale motions in turbulent boundary layer by temporal resolution particle image velocimetry J. Turbul. (IF 1.9) Pub Date : 2022-05-24 Ziye Fan, Zhanqi Tang, Xingyu Ma, Nan Jiang
Experiments of particle image velocimetry (PIV) in the turbulent boundary layer at Reτ=400∼1000 have been conducted to investigate the convection characteristic of turbulent structure and the validity of Taylor’s hypothesis. Views of 6δ×1.2δ ( δ=δ99, the boundary layer thickness) were captured by four streamwise-arranged cameras. Distributions of streamwise turbulent kinetic energy on a streamwise
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Dependence of wall jet phenomenology on inlet conditions and near-field flow development J. Turbul. (IF 1.9) Pub Date : 2022-05-06 Sarvesh Kumar, Amitesh Kumar
In this paper, the three-dimensional turbulent wall jet flow is investigated for three different developing initial velocity profiles. k− The developing initial velocity profiles at the nozzle exit are generated by three different lengths ( l/h=10, 50 and 90) of the square nozzle (20±0.5mm×20±0.5mm). The velocity profiles at the nozzle exit are measured with the single probe hot-wire anemometer. The
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Build up of yield stress fluids via chaotic emulsification J. Turbul. (IF 1.9) Pub Date : 2022-05-06 Ivan Girotto, Roberto Benzi, Gianluca Di Staso, Andrea Scagliarini, Sebastiano Fabio Schifano, Federico Toschi
Stabilised dense emulsions display a rich phenomenology connecting microstructure and rheology. In this work, we study how an emulsion with a finite yield stress can be built via large-scale stirring. By gradually increasing the volume fraction of the dispersed minority phase, under the constant action of a stirring force, we are able to achieve a volume fraction close to 80%. Despite the fact that
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Dimension reduced turbulent flow data from deep vector quantisers J. Turbul. (IF 1.9) Pub Date : 2022-04-11 Mohammadreza Momenifar, Enmao Diao, Vahid Tarokh, Andrew D. Bragg
Analysing large-scale data from simulations of turbulent flows is memory intensive, requiring significant resources. This major challenge highlights the need for data compression techniques. In this study, we apply a physics-informed Deep Learning technique based on vector quantisation to generate a discrete, low-dimensional representation of data from simulations of three-dimensional turbulent flows
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Large eddy simulations of single and multiple turbulent round jets J. Turbul. (IF 1.9) Pub Date : 2022-04-01 G. K. Balajee, N. R. Panchapakesan
We present results from three large eddy simulations (LES). The first two were those of a single jet at a Reynolds number of 11000 with different cell density distributions. The simulation results are validated with earlier experimental and computational studies at the same Reynolds number and almost the same boundary conditions. We establish the repeatability and reproducibility of the characterisation
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Effect of the Froude number on a stratified turbulence under two shear orientations using coupled SSG and SL models J. Turbul. (IF 1.9) Pub Date : 2022-03-29 Lamia Thamri, Taoufik Naffouti
In the present investigation, the evolution of homogeneous and stratified turbulence under a horizontal and a vertical shear is deliberate by coupled second-order model SSG-SL. This model is a result of a combination between the Speziale, Sarkar and Gatski model (SSG) and the Shih and Lumley model (SL). Horizontal shear and vertical shear are related to the angle between the shear and the vertical
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Modulation of turbulent Couette flow with vortex cavitation in a minimal flow unit J. Turbul. (IF 1.9) Pub Date : 2022-03-08 Takashi Ohta, Fumiya Osaka, Yuta Kitagawa
Modulation of turbulent flow by cavitation in fluid machinery can cause vibrations, noise, and erosion. In this study, we confirm the cavitation phenomenon and observe its characteristics to predict the flow and control it accordingly. We perform a direct numerical simulation of the turbulent Couette flow of water with vortex cavitation using a cavitation model to predict phase change based on pressure
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On turbulent flow and aerodynamic noise of generic side-view mirror with cell-centred finite difference method J. Turbul. (IF 1.9) Pub Date : 2022-03-01 Fei Liao
This paper investigates the turbulent flow and aerodynamic noise of a half-cylinder body mounted on a flat plate at Re=5.2×105 using high-order cell-centred finite difference method with delayed detached-eddy simulation (DDES) and large-eddy simulation (LES). Transient flow patterns from the two simulations are found to be very different in consideration of the small-scale structures. The profiles
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A prediction method for spatially decaying freestream turbulence J. Turbul. (IF 1.9) Pub Date : 2022-02-27 D. Sarkar, E. Savory
A simple set of equations, capable of quantifying and predicting the spatial decay of freestream turbulence (FST) is derived in the current study. The prediction equations are based on the inviscid estimate of the turbulent kinetic energy (TKE) dissipation rate. The new set of model equations includes the integral length scale and the turbulent kinetic energy as variables and is superior to the previous
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Turbulence anisotropy around bridge piers in seepage affected sand bed channel J. Turbul. (IF 1.9) Pub Date : 2022-01-20 Rutuja Chavan, Anurag Sharma, Bimlesh Kumar
In this work, experimental investigations have been pursued to analyse the Reynolds stress anisotropy in the flow around the bridge pier for no seepage and downward seepage. Experiments were conducted in the non-uniform sand bed channel with circular piers of 75 mm diameter. The streamwise velocity and Reynolds Shear Stress was observed to be maximum near the edge at upstream and near the bed at downstream
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Enhanced outer peaks in turbulent boundary layer using uniform blowing at moderate Reynolds number J. Turbul. (IF 1.9) Pub Date : 2022-01-18 Gazi Hasanuzzaman, Sebastian Merbold, Vasyl Motuz, Christoph Egbers
Uniform blowing through a permeable surface acts as an active flow control method in wall bounded flows. Such control technique was investigated in a zero pressure gradient turbulent boundary layer over a flat plate. Measurement data were obtained with the help of Laser Doppler Anemometry technique. Besides the drag reduction characteristics of such flow control method, time averaged measurement of
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A multispecies turbulence model for the mixing and de-mixing of miscible fluids J. Turbul. (IF 1.9) Pub Date : 2021-10-15 N. O. Braun, R. A. Gore
A de-mix capable model for turbulence in compressible, variable density flows is proposed. The model is based on the Besnard-Harlow-Rauenzahn (BHR) family of models (Besnard D, Harlow F, Rauenzahn R, et al. Turbulence transport equations for variable-density turbulence and their relationship to two-field models. NM (United States): Los Alamos National Laboratory; 1992 (Technical Report LA-12303-MS)
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Hydrodynamics of flow through a degraded channel bed J. Turbul. (IF 1.9) Pub Date : 2021-12-03 Mosedul Sarkar, Saurabh Kumar Maurya, Partha P. Gopmandal, Sankar Sarkar
This article presents experimental results of turbulent flow measured in a bimodal degraded channel bed consisting of sand-gravel mixture. Sand and gravel of uniform sizes 0.25 and 3.5 mm were mixed in the same proportions (by weight) to create a bimodal sedimentary bed. A three-dimensional Vectrino velocimeter was employed to collect three-dimensional velocities over bimodal degraded bed under equilibrium
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Investigation on turbulent characteristic of crossflow under suction in a T-junction using Holo-Hilbert spectral analysis J. Turbul. (IF 1.9) Pub Date : 2021-12-04 Xuefang Xu, Huaishuang Shao, Ruixiong Li, Mei Lin, Peiming Shi
To investigate the crossflow of ventilation in high-speed train, a T-junction experimental setup is built and velocity data of crossflow under different conditions and positions are measured. Specifically, the conditions include the different velocities of crossflow and different intensities of suction, and the positions include upstream, mid-centre, and downstream. To give full information of the
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Convolutional neural network models and interpretability for the anisotropic reynolds stress tensor in turbulent one-dimensional flows J. Turbul. (IF 1.9) Pub Date : 2021-11-10 Haitz Sáez de Ocáriz Borde, David Sondak, Pavlos Protopapas
The Reynolds-averaged Navier-Stokes (RANS) equations are widely used in turbulence applications. They require accurately modelling the anisotropic Reynolds stress tensor, for which traditional Reynolds stress closure models only yield reliable results in some flow configurations. In the last few years, there has been a surge of work aiming at using data-driven approaches to tackle this problem. The