Searched for: subject:"turbulence"
(1 - 20 of 345)

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Kaller, Thomas (author), Pasquariello, Vito (author), Hickel, S. (author), Adams, Nikolaus A. (author)
and an average Nusselt number of Nuxz = 371. The geometry and boundary conditions follow an experimental reference case and good agreement...
journal article 2019
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Oude Nijhuis, A.C.P. (author)
Scanning radars are promising sensors for atmospheric remote sensing, giving potential to retrieve parameters that characterize the local air dynamics during rain. For the observation of air motion, radars are relying on the backscatter of particles, which can, for example, be raindrops or insects. To measure wind vectors and turbulence...
doctoral thesis 2019
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Elsinga, G.E. (author), da Silva, C.B. (author)
The average patterns of the velocity and scalar fields near turbulent/non-turbulent interfaces (TNTI), obtained from direct numerical simulations (DNS) of planar turbulent jets and shear free turbulence, are assessed in the strain eigenframe. These flow patterns help to clarify many aspects of the flow dynamics, including a passive scalar,...
journal article 2019
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Benschop, H.O.G. (author), Greidanus, A.J. (author), Delfos, R. (author), Westerweel, J. (author), Breugem, W.P. (author)
We investigate the deformation of a linear viscoelastic compliant coating in a turbulent flow for a wide range of coating parameters. A one-way coupling model is proposed in which the turbulent surface stresses are expressed as a sum of streamwise-travelling waves with amplitudes determined from the stress spectra of the corresponding flow...
journal article 2019
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Mehta, D. (author), Zhang, Y. (author), van Zuijlen, A.H. (author), Bijl, H. (author)
Despite advances in turbulence modelling, the Smagorinsky model remains a popular choice for large eddy simulation (LES) due to its simplicity and ease of use. The dissipation in turbulence energy that the model introduces, is proportional to the Smagorinsky constant, of which many different values have been proposed. These values have been...
journal article 2019
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Kurelek, J.W. (author), Kotsonis, M. (author), Yarusevych, S. (author)
Transition and flow development in a separation bubble formed on an airfoil are studied experimentally. The effects of tonal and broadband acoustic excitation are considered since such acoustic emissions commonly result from airfoil self-noise and can influence flow development via a feedback loop. This interdependence is decoupled, and the...
journal article 2018
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van Hooijdonk, I.G.S. (author), Clercx, Herman J.H. (author), Ansorge, Cedrick (author), Moene, Arnold F. (author), van de Wiel, B.J.H. (author)
We perform direct numerical simulation of the Couette flow as a model for the stable boundary layer. The flow evolution is investigated for combinations of the (bulk) Reynolds number and the imposed surface buoyancy flux. First, we establish what the similarities and differences are between applying a fixed buoyancy difference (Dirichlet) and...
journal article 2018
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van Beinum, A.S. (author), Farah, H. (author), Wegman, F.C.M. (author), Hoogendoorn, S.P. (author)
In the vicinity of ramps, drivers make route choices, change lanes and in most cases also adjust their speeds. This can trigger anticipatory behaviour by the surrounding vehicles, which are also reflected in lane changes and/or changes in speed. This phenomenon is called turbulence and is widely recognised by the scientific literature and...
journal article 2018
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Fujimura, Atsushi G. (author), Reniers, A.J.H.M. (author), Paris, Claire B. (author), Shanks, Alan L. (author), MacMahan, Jamie H. (author), Morgan, Steven G. (author)
We investigated whether cross-shore distributions of coastal phytoplankton to the surf zone are controlled by hydrodynamics and their biological characteristics. Data from a rip-channeled beach indicate that concentrations of phytoplankton are higher in the surf zone than offshore. To examine how phytoplankton is transported toward the shore,...
journal article 2018
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Serpieri, J. (author), Kotsonis, M. (author)
In this study, experiments are performed towards the identification and measurement of unsteady modes occurring in a transitional swept wing boundary layer. These modes are generated by the interaction between the primary stationary and travelling cross-flow instabilities or by secondary instability mechanisms of the stationary cross-flow...
journal article 2018
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Ye, Q. (author), Schrijer, F.F.J. (author), Scarano, F. (author)
The variation of transitional flow features past a micro-ramp is investigated when the Reynolds number is decreased approaching the critical regime. Experiments are conducted in the incompressible flow spanning from supercritical to subcritical roughness-height-based Reynolds number ( , 730, 460 and 320) with tomographic particle image...
journal article 2018
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van Hooft, J.A. (author), Popinet, Stéphane (author), van Heerwaarden, Chiel C. (author), van der Linden, S.J.A. (author), de Roode, S.R. (author), van de Wiel, B.J.H. (author)
We present a proof-of-concept for the adaptive mesh refinement method applied to atmospheric boundary-layer simulations. Such a method may form an attractive alternative to static grids for studies on atmospheric flows that have a high degree of scale separation in space and/or time. Examples include the diurnal cycle and a convective...
journal article 2018
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Gül, M. (author), Elsinga, G.E. (author), Westerweel, J. (author)
This paper describes the hysteresis in the torque for Taylor–Couette flow in the turbulent flow regime for different shear Reynolds numbers, aspect ratios and boundary conditions. The hysteresis increases with decreasing shear Reynolds number and becomes more pronounced as the aspect ratio is increased from 22 to 88. Measurements conducted in...
journal article 2018
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Silvestri, S. (author), Patel, A. (author), Roekaerts, D.J.E.M. (author), Pecnik, R. (author)
The present work consists of an investigation of the turbulence radiation interaction (TRI) in a radiative turbulent channel flow of grey gas bounded by isothermal hot and cold walls. The optical thickness of the channel is varied from 0.1 to 10 to observe different regimes of TRI. A high-resolution finite volume method for radiative heat...
journal article 2018
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van Hout, R.L.H. (author), Eisma, H.E. (author), Elsinga, G.E. (author), Westerweel, J. (author)
In many applications, finite-sized particles are immersed in a turbulent boundary layer (TBL) and it is of interest to study wall effects on the instantaneous shedding of turbulence structures and associated mean velocity and Reynolds stress distributions. Here, 3D flow field dynamics in the wake of a prototypical, small sphere (D+=50, 692<...
journal article 2018
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Goudar Vishwanathappa, M. (author), Elsinga, G.E. (author)
The motion of tracer particles is kinematically simulated around three elementary flow patterns; a Burgers vortex, a shear-layer structure with coincident vortices and a node-saddle topology. These patterns are representative for their broader class of coherent structures in turbulence. Therefore, examining the dispersion in these elementary...
journal article 2018
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Charruault, F.T. (author), Greidanus, A.J. (author), Breugem, W.P. (author), Westerweel, J. (author)
The present study introduces an experimental technique based on a Free Surface-Synthetic Schlieren (FS-SS) method in order to characterize free surfaces subjected to strong deformations. Current synthetic Schlieren methods are based on local image correlation and thus limited to rather weak image deformations, implying that they can only resolve...
conference paper 2018
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Otero Rodriguez, G.J. (author), Patel, A. (author), Diez Sanhueza, Rafael (author), Pecnik, R. (author)
This paper presents a novel methodology for improving eddy viscosity models in predicting wall-bounded turbulent flows with strong gradients in the thermo-physical properties. Common turbulence models for solving the Reynolds-averaged Navier–Stokes equations do not correctly account for variations in transport properties, such as density and...
journal article 2018
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Stoter, Stein K.F. (author), Turteltaub, S.R. (author), Hulshoff, S.J. (author), Schillinger, Dominik (author)
We initiate the study of the discontinuous Galerkin residual-based variational multiscale (DG-RVMS) method for incorporating subgrid-scale behavior into the finite element solution of hyperbolic problems. We use the one-dimensional viscous Burgers equation as a model problem, as its energy dissipation mechanism is analogous to that of turbulent...
journal article 2018
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Argyle, Peter (author), Watson, S.J. (author), Montavon, Christiane (author), Jones, Ian (author), Smith, Megan (author)
The IEC standard 61400-1 edition 3 uses the so-called Frandsen model to assess levels of turbulence intensity (TI) within wind farms, specifically to determine turbine suitability associated with stress and fatigue. Since the Frandsen model was developed, turbines have significantly grown in size and the number of turbines in an individual wind...
journal article 2018
Searched for: subject:"turbulence"
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