Turbulent flow in a ribbed channel: Flow structures in the vicinity of a rib

Wang, Lei; Salewski, M.; Sundén, Bengt

doi:10.1016/j.expthermflusci.2009.10.005

Cited by 56 publications

(15 citation statements)

References 20 publications

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“…The increased inclination is also consistent with a reduced streamwise correlation over this surface (not shown here). This has already been observed both experimentally and numerically by Grass, Stuart & Mansour-Thehrani (1993), Krogstad & Antonia (1994), Leonardi et al (2004), Coceal et al (2006), Wang, Salewski & Sundén (2010) and Hong, Katz & Schultz (2011). The contours are more circular than for a smooth wall, thus indicating an increase in isotropy, which is consistent with the anisotropy invariant map of Smalley et al (2002).…”

Section: Thermal and Velocity Coherent Structuressupporting

confidence: 72%

Heat transfer in a turbulent channel flow with square bars or circular rods on one wall

et al. 2015

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Direct numerical simulations (DNS) are carried out to study the passive heat transport in a turbulent channel flow with either square bars or circular rods on one wall. Several values of the pitch (λ) to height (k) ratio and two Reynolds numbers are considered. The roughness increases the heat transfer by inducing ejections at the leading edge of the roughness elements. The amounts of heat transfer and mixing depend on the separation between the roughness elements, an increase in heat transfer accompanying an increase in drag. The ratio of non-dimensional heat flux to the non-dimensional wall shear stress is higher for circular rods than square bars irrespectively of the pitch to height ratio. The turbulent heat flux varies within the cavities and is larger near the roughness elements. Both momentum and thermal eddy diffusivities increase relative to the smooth wall. For square cavities (λ/k = 2) the turbulent Prandtl number is smaller than for a smooth channel near the wall. As λ/k increases, the turbulent Prandtl number increases up to a maximum of 2.5 at the crests plane of the square bars (λ/k = 7.5). With increasing distance from the wall, the differences with respect to the smooth wall vanish and at three roughness heights above the crests plane, the turbulent Prandtl number is essentially the same for smooth and rough walls.

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Section: Thermal and Velocity Coherent Structuressupporting

confidence: 72%

Heat transfer in a turbulent channel flow with square bars or circular rods on one wall

et al. 2015

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“…However, at this location behind a 3D wall-mounted cube [Hearst et al (2016)], the wake of the obstacle is fully dissipated as the wake is less impacted by side effect and thus extends. Finally, the experimental works of [Wang et al (2009)] offer a topology of the fluid past a rib at R e = 2.2 × 10 4 . However, few studies focus on the wake development of finite length square cylinder cases.…”

Section: Introductionmentioning

confidence: 99%

Experimental investigation of the turbulent wake past real seabed elements for velocity variations characterization in the water column.

Ikhennicheu

Germain

Druault

et al. 2019

International Journal of Heat and Fluid Flow

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“…Numerous early studies have essentially concentrated on square (or rectangular) shaped ribs and investigated the effects of aforementioned geometrical parameters on the heat and flow performance [6][7][8][9][10][11][12][13][14][15]. Several investigations comparing different shaped ribs have been performed in order to identify the shape effect on the heat transfer mechanism for ribbed channels.…”

Section: Introductionmentioning

confidence: 99%

Particle image velocimetry and proper orthogonal decomposition analysis of the channel flow equipped with cylindrical ribs

Gürlek¹

2017

THERM SCI

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Original scientific paper https://doi.org/10.2298/TSCI170305204GThe characteristics of the flow fields in a rectangular channel equipped with cylindrical ribs were examined through the particle image velocimetry experiments. The mean and turbulence characteristics were presented for three different Reynolds numbers of 2900, 8400, and 15000. In addition, the coherent flow structures were extracted by means of the proper orthogonal decomposition method. The flow field is characterized by a large re-circulation region and a secondary clockwise-rotating corner vortex. The high vorticity, fluctuation velocity and shear stress contours are formed along the free shear layers emanating from the upstream rib. As Reynolds numbers increase, the positive vorticity contours extend downstream and fluctuation velocity and shear stress contours spread out towards the channel wall. The proper orthogonal decomposition results have shown that a horizontally aligned co-rotating vortex pair and a corner vortex are the dominant flow structures for the highest Reynolds number.

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Turbulent flow in a ribbed channel: Flow structures in the vicinity of a rib

Cited by 56 publications

References 20 publications

Heat transfer in a turbulent channel flow with square bars or circular rods on one wall

Heat transfer in a turbulent channel flow with square bars or circular rods on one wall

Experimental investigation of the turbulent wake past real seabed elements for velocity variations characterization in the water column.

Particle image velocimetry and proper orthogonal decomposition analysis of the channel flow equipped with cylindrical ribs

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