Flow past confined delta-wing type vortex generators

Akcayoglu, Azize

doi:10.1016/j.expthermflusci.2010.08.012

Cited by 30 publications

(18 citation statements)

References 43 publications

(46 reference statements)

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“…They reported that the average Nusselt number of plate with attack angle of 60 is slightly higher than that of plate with attack angle of 45 yet may bring larger pressure drop. Akcayoglu [19] performed an investigation about the heat transfer enhancement in a PFHE with triangular fins as insert using a winglet pair of vortexgenerator. It was confirmed that the average Nusselt number increases with an increase in the angle of attack and Reynolds number.…”

Section: Introductionmentioning

confidence: 99%

Performance of a plate-fin heat exchanger with vortex-generator channels: 3D-CFD simulation and experimental validation

Khoshvaght-Aliabadi

Zangouei

Hormozi

2015

International Journal of Thermal Sciences

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Section: Introductionmentioning

confidence: 99%

Performance of a plate-fin heat exchanger with vortex-generator channels: 3D-CFD simulation and experimental validation

Khoshvaght-Aliabadi

Zangouei

Hormozi

2015

International Journal of Thermal Sciences

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“…The span-average NUs is obtained by averaging span strip fin and tube surfaces at position x (16) iocai over the…”

Section: Momentum Equationsmentioning

confidence: 99%

“…There are many methods for the heat transfer enhancement of fin surfaces [4][5][6][7][8][9][10][11][12][13][14][15][16]. Mounting or punching (VGs) on heat transfer surfaces is another effective method to generate secondary flow and to enhance convective heat transfer [6][7][8][9][10][11][12][13][14][15][16]. These studies reported the effects of the VG shapes, the attack angle of VGs, and the arrangement of VGs on convective heat transfer performances of different heat transfer surfaces.…”

Section: Introductionmentioning

confidence: 99%

The Effectiveness of Secondary Flow Produced by Vortex Generators Mounted on Both Surfaces of the Fin to Enhance Heat Transfer in a Flat Tube Bank Fin Heat Exchanger

Song

Wang

2013

Journal of Heat Transfer

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Secondary flow is the flow in the cross section normal to the main flow, ¡t plays an important role on the enhanced heat transfer and in the applications in other flelds. Secondary flow can greatly enhance the convective heat transfer. In order toflnd the effectiveness of secondary flow for heat transfer enhancement, a nondimensional parameter. Se, based on the ab.wlute vorticity flux is reported to specify the intensity of secondaiy flow. Its physical meaning is the ratio of inertial force to viscous force induced by secondary flow. As an example, the effectiveness of secondary flow was numerically studied for a flat tube bank fln heat exchanger with vortex generators (VGs) mounted on both surfaces of the fln. The contributions of VGs are investigated for the enhancements of secondary flow intensity, convective heat transfer, and pressure drop. The method is demonstrated using Se toflnd out the optimum conflgurations of VGs. The results reveal that close relationships exist not only between the span-average nondimensional intensity of secondary flow and the span-average Nusselt number but also between the volume average nondimensional intensity of secondary flow and the overall average Nusselt number. For the conflguration studied, a ratio of Nusselt number enhancement to the friction factor enhancement increases with increasing the enhancement of secondary flow intensity. As a supplement to traditional criteria on a good performance heat transfer surface, the nondimensional intensity of secondary flow can be used dearly for an optimum value of VG parameter.

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“…7–14 Some investigators concentrated on the effects of orientations of the VGs. 15–24 If spanwise distance between the leading edges of a VG pair is wider than the trailing edges, then this orientation is called common flow up (CFU), and if spanwise distance between the leading edges of a VG pair is narrower than the trailing edges, then this orientation is called common flow down (CFD). 25 It is interesting that there are conflicts between the investigators on the best orientation of VGs.…”

Section: Introductionmentioning

confidence: 99%

Thermal enhancement of triangular fins based on spanwise distance of vortex generators

Akcayoglu

Nazli

2016

Proceedings of the Institution of Mechanical Engineers, Part C:

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In this study, the influence of spanwise positions of vortex generators on the fin performance is determined numerically by considering global and local flow and heat transfer fields. The vortex generators are located on the inclined surfaces of equilateral triangular fins and the spanwise distances between them are altered as much as possible depending on the extents of the triangular duct. “RNG k-ɛ” turbulence model with “Enhanced wall treatment” option is determined as the best turbulence model to predict the flow fields inside the triangular fins with built-in vortex generators, for Reynolds number of 5000. It is found that the best performance is achieved when the spanwise distance between the common flow up and common flow down type vortex generator pairs and the triangular duct base are equal to 0.23 and 1.11 times the vortex generator length, respectively. The optimum spanwise distance between the vortex generators is determined as 0.88 times the vortex generator length. The determined values reinforced the secondary flow interactions including mixing of hot and cold fluids, generation of turbulence, swirling motion of vortices, and interaction of vortices with the main flow. The obtained results are useful in designing triangular heat exchangers with built-in delta-winglet type vortex generators.

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Flow past confined delta-wing type vortex generators

Cited by 30 publications

References 43 publications

Performance of a plate-fin heat exchanger with vortex-generator channels: 3D-CFD simulation and experimental validation

Performance of a plate-fin heat exchanger with vortex-generator channels: 3D-CFD simulation and experimental validation

The Effectiveness of Secondary Flow Produced by Vortex Generators Mounted on Both Surfaces of the Fin to Enhance Heat Transfer in a Flat Tube Bank Fin Heat Exchanger

Thermal enhancement of triangular fins based on spanwise distance of vortex generators

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