Analysis of Turbulent Boundary Layers

Cebeci, Tuncer; Smith, A. M. O.; Libby, Paul A.

doi:10.1115/1.3423784

Cited by 116 publications

(173 citation statements)

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“…Morkovin [1] proposed strong Reynolds analogy (SRA) relations, four of which are listed below: In further developments that are based on considering the influence of the heat flux on the wall or eliminating the influence of the wall temperature, modified SRA relations have been proposed. For example, Cebeci and Smith [20] derived an extended SRA (ESRA) based on eq. (7):…”

Section: Reynolds Analogiesmentioning

confidence: 99%

DNS of a spatially evolving hypersonic turbulent boundary layer at Mach 8

Liang

2013

Sci. China Phys. Mech. Astron.

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This paper reports the direct numerical simulation (DNS) for hypersonic turbulent boundary layer over a flat-plate at Ma ∞ =8 with the ratio of wall-to-freestream temperature equal to 1.9, which indicates an extremely cold wall condition. It is primarily used to assess the wall temperature effects on the mean velocity profile, Walz equation, turbulent intensity, strong Reynolds analogy (SRA), and compressibility. The present high Mach number with cold wall condition induces strong compressibility effects. As a result, the Morkovin's hypothesis is not fully valid and so the classical SRA is also not fully consistent. However, some modified SRA is still valid at the far-wall region. It is also verified that the semi-local wall coordinate y * is better than conventional y + in analysis of statistics features in turbulent boundary layer (TBL) in hypersonic flow. DNS, compressibility effects, turbulent boundary layer PACS number(s): 47

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Section: Reynolds Analogiesmentioning

confidence: 99%

DNS of a spatially evolving hypersonic turbulent boundary layer at Mach 8

Liang

2013

Sci. China Phys. Mech. Astron.

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“…The value of a spectrum at a certain frequency or wavelength equates to the mean energy of that wave, and as a result, it provides a means of assessing how eddies of different sizes exchange energy and how turbulence evolves with time. With turbulence being a largely three-dimensional problem, this necessitates construction of energy spectra in three dimensions (Cebeci and Smith, 1974) . Figure 5 shows the power spectral densities (PSD) of the three fluctuating velocity components (u' wave )…”

Section: Spectral Analysis Of Turbulence and Suspensionmentioning

confidence: 99%

Wave-induced coherent turbulence structures and sediment resuspension in the nearshore of a prototype-scale sandy barrier beach

Kassem

Thompson

Amos

et al. 2015

Continental Shelf Research

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Abstract:The suspension of sediments by oscillatory flows is a complex case of fluid-particle interaction. The aim of this study is to provide insight into the spatial (time) and scale (frequency) relationships between wave-generated boundary layer turbulence and eventdriven sediment transport beneath irregular shoaling and breaking waves in the nearshore of a prototype sandy barrier beach, using data collected through the Barrier Dynamics Experiment II (BARDEX II). Statistical, quadrant and spectral analyses reveal the anisotropic and intermittent nature of Reynolds' stresses (momentum exchange) in the wave boundary layer, in all three orthogonal planes of motion. The fractional contribution of coherent turbulence structures appears to be dictated by the structural form of eddies beneath plunging and spilling breakers, which in turn define the net sediment mobilisation towards or away from the barrier, and hence ensuing erosion and accretion trends. A standing transverse wave is also observed in the flume, contributing to the substantial skewness of spanwise turbulence. Observed low frequency suspensions are closely linked to the mean flow (wave) properties. Wavelet analysis reveals that the entrainment and maintenance of sediment in suspension through a cluster of bursting sequence is associated with the passage of intermittent slowly-evolving large structures, which can modulate the frequency of smaller motions. Outside the boundary layer, small scale, higher frequency turbulence drives the suspension. The extent to which these spatially varied perturbation clusters persist is associated with suspension events in the high frequency scales, decaying as the turbulent motion ceases to supply momentum, with an observed hysteresis effect. The suspension of sediment in turbulent flows is a complex case of fluid-particle interaction, governed by shear stresses (momentum exchanges) at the bed and within the benthic boundary layer (BBL). Defining the physical processes which dictate the resuspension of sediments in coastal and estuarine settings is fundamental for accurate predictions of bed morphology evolution (Van Rijn et al., 2007), and has profound implications for the biogeochemical processes that shape their local ecology (Thompson et al., 2011). It is also a prerequisite to quantifying erosion and deposition trends, and hence guiding engineering applications such as beach nourishment, defence schemes against erosion and flooding, maintenance of marine infrastructure and waterways, and aggregate dredging. There is a genuine need for better, robust models of suspended sediment transport in the coastal zone (Aagaard and Jensen, 2013). In a vision paper on future research needs in coastal dynamics, Van Rijn et al. (2013) highlighted the pressing need for research to support such models, focusing in particular on sand transport in the shoreface (non-breaking waves), surf and swash zones; employing field and controlled laboratory experiments.The mobilisation of sediments in the nearshore and shoreface is dominated b...

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“…For a small-scale roughness condition, a two-dimensional openchannel flow [Cebeci and Smith, 1974], and a fully developed turbulent flow [Kirkg6z and Ardi•hoglu, 1997], two regions can be distinguished: (1) a near-wall, or inner, region (z <-0.1-0.2, z being the relative depth equal to the ratio between the distance y from the bottom and the uniform flow depth h) and (2) a near-water surface, or outer, region (0.1-0.2 < z <-1).…”

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confidence: 99%

Incomplete self‐similarity and flow velocity in gravel bed channels

Ferro¹,

Pecoraro²

2000

Water Resources Research

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Abstract. Velocity measurements, previously carried out using both a miniature current flowmeter and an acoustic Doppler velocimeter, are used to verify the applicability of the incomplete self-similarity theory to deduce the velocity profile in a gravel bed channel. Then, for the velocity profiles having the maximum value below the free surface and for the S-shaped profiles, the power velocity distribution is corrected using a new divergence function. For each value of the depth sediment ratio the nondimensional friction factor parameter is calculated by integration of the measured velocity distributions in the different verticals of the cross section. Finally, a semilogarithmic flow resistance equation is empirically deduced.

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Analysis of Turbulent Boundary Layers

Abstract: The uniqueness of the solution can be proved as follows: Suppose that 4>i(x) and $z(x) are two solutions such that *i(x) = f(x) + ("" K(x, sfaWds,

Cited by 116 publications

References 0 publications

DNS of a spatially evolving hypersonic turbulent boundary layer at Mach 8

DNS of a spatially evolving hypersonic turbulent boundary layer at Mach 8

Wave-induced coherent turbulence structures and sediment resuspension in the nearshore of a prototype-scale sandy barrier beach

Incomplete self‐similarity and flow velocity in gravel bed channels

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