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Showing 1 to 14 of 14 for “"wall-bounded turbulence"”.
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Statistical Stability and Fast Transient Growth in Wall-Bounded Turbulence
Shear-driven turbulence can be generated in wall-bounded flows due to the non-slip boundary. The simple geometry of a wall and thus the shear-driven turbulence are ubiquitous in nature and engineering applications. Hence, prediction and modelling of the turbulence appearance and maintenance in …
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Numerical study of mach number effects in compressible wall-bounded turbulence
… understanding of compressibility effects in wall-bounded turbulence and to provide data for improving models. A family of wall-bounded compressible flows has been investigated using direct numerical simulation (DNS). The research is divided into two aspects: a study of the intrinsic …
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A Filtered-Wall Formulation for Large -Eddy Simulation of Wall -Bounded Turbulence
… turbulent flows where only the largest scales of turbulence are simulated, while the effects of the small scales are modeled. However, the application of LES in engineering flows is limited largely by difficulties in LES modeling near walls; this is commonly known as the LES 'wall-modeling' …
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The dynamics of the outer region of wall-bounded turbulence : La dinámica de la zona exterior en la turbulencia de pared
… analysis of the dynamics of the outer region of wall-bounded flows, focusing on the interaction between the inner- and outer- layers. The primary tool used in the present study is a set of Direct Numerical Simulations (DNS) of turbulent channels with friction Reynolds number Reτ ≈ 630. In those …
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Very -Large -Scale Motions in Wall -Bounded Turbulent Flows
… packets is a robust and significant feature of wall-bounded turbulence over a wide range of Reynolds numbers. The hairpin-vortex-packet model of turbulence provides a consistent explanation for the distribution of energy among the largest scales of the flow and underscores the importance of the …
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Polymers and plastrons : active and passive drag reduction in wall-bounded turbulent flows
Frictional energy dissipation in wall-bounded turbulence is ubiquitous in modern engineering systems, ranging from the flow of liquids through pipelines, to the drag-inducing boundary layer around ships and submarines. The effective mitigation of this frictional drag is therefore of great practical …
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Numerical Investigation of turbulent coupling boundary layer of air-water interaction flow
… differences between air-water interface turbulence near the water side (IntT-w) and wall-bounded turbulence(WT) while there are some similarities between IntT-w and free surface turbulence (FST). Due to the velocity fluctuation at the interface, water side near interface turbulence flow …
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Wall-modeled Large-eddy Simulation Based on Building-block Flows
A unified subgrid-scale (SGS) and wall model—the building-block flow model (BFM) — for wall modeled large-eddy simulation (WMLES) is proposed by devising the flow as a collection of building blocks that enables the prediction of the eddy viscosity. The core assumption of the model is that simple …
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Spectral modeling of an idealized atmospheric surface layer
… modelling a broad range of turbulent motions in wall-bounded turbulent flows such as the ASL, using spectra of turbulent fluctuations as inputs. Turbulent spectra contain information on turbulent motions across scales, and are constrained by theory and observations. By propagating spectra through …
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The influence of superhydrophobic surfaces on near-wall turbulence
… slip and the texturing of the surface have on turbulence over superhydrophobic surfaces. It is shown that, after filtering out the texture-induced flow, the background, overlying turbulence experiences the surface as a homogeneous slip boundary condition. For texture sizes, expressed in wall …
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Control of the buffer and logarithmic layers in wall-bounded turbulent flows
… separately the buffer and logarithmic layers in wall-bounded turbulent flows. In the case of buffer-layer control, we examine the effect on near-wall turbulence of displacing the apparent, virtual origins perceived by different components of the overlying flow. This mechanism is commonly reported …
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Vortex detection and tracking in massively separated and turbulent flows
… and consistent analysis. For a simulation of wall-bounded turbulence in a channel flow, tracking FTLE-saddles shows that the average structure convection speed exhibits a similar trend as a previously published result based on velocity and pressure correlations, giving validity to the method. …
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Subgrid Scale Modeling for Large Eddy Simulation of Buoyant Turbulent Flows
… measures of important quantities such as turbulence budgets, in a simplified flow configuration involving buoyancy effects on a turbulent flow.</p> <p>Three existing LES SGS models for buoyant turbulent flows are assessed by performing LES and comparing the results to DNS data found in the …
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Multiphase Flow Dynamics in Confined Domains—A DNS Study of Bubbly, Thermal and Riblet-Induced Turbulence
… a comprehensive investigation of multiphase and wall-bounded turbulent flows using high-fidelity direct numerical simulations (DNS), with an emphasis on the fundamental mechanisms governing heat transfer, turbulence modulation, and instability-driven transition. By systematically studying three …