Numerical simulation on performances of plane and curved winglet type vortex generator pairs with punched holes

Lu, Gaofeng; Zhou, Guobing

doi:10.1016/j.ijheatmasstransfer.2016.06.063

Cited by 112 publications

(27 citation statements)

References 28 publications

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“…The results showed that the wavy fin with delta winglet pairs can significantly enhance air-side heat transfer and pressure drop [18]. Thermal characteristics of the plan and curved vortex generators with or without punching holes in the fin surface were investigated, indicating that vortex generators with holes have higher heat transfer enhancement and lower pressure drop than those without holes [19]. In order to resolve the shortcomings of the louver fin heat exchanger, Chan Hyeok Jeong developed the plate fin with both ceases and holes, which helped to improve heat transfer and could be used under hostile environments [20].…”

Section: Introductionmentioning

confidence: 99%

On the Heat Transfer Enhancement of Plate Fin Heat Exchanger

Xue

et al. 2018

Energies

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The plate fin heat exchanger is a compact heat exchanger applied in many industries because of its high thermal performance. To enhance the heat transfer of plate fin heat exchanger further, three new kinds of wavy plate fins, namely perforated wavy fin, staggered wavy fin and discontinuous wavy fin, are proposed and investigated by computational fluid dynamics (CFD) simulations. The effects of key design parameters, including that of waviness aspect ratios, perforation diameters, staggered ratios and breaking distance are investigated, respectively, with Reynolds number changes from 500 to 4500. It is found that due to the swirl flow and efficient mixing of the fluid, the proposed heat transfer enhancement techniques all have advantages over the traditional wavy fin. At the same time, serration is beneficial to reduce the friction factor, and the breaking technique can reduce heat transfer area. Through the performance evaluation criteria, the staggered wavy fin has an advantage over the small waviness aspect ratio; with increasing waviness aspect ratio, this predominance is gradually surpassed by the perforated wavy fin, and the advantage of the discontinuous fin is the smallest and almost invariable. A maximum performance evaluation criteria (PEC) as high as 1.24 can be obtained for the perforated wavy fin at the waviness aspect ratio γ = 0.45.

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Section: Introductionmentioning

confidence: 99%

On the Heat Transfer Enhancement of Plate Fin Heat Exchanger

Xue

et al. 2018

Energies

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“…The time variation of the rate of heat transfer was of the order of 10 À4 W which is negligible. The steady laminar flow assumption was also made in several studies from the open literature such as Lu and Zhou [21] and Dezan et al [22]. Moreover, additional numerical simulations were run for the empty channel computational domain for both Reynolds numbers and for two different cases: in the first the density is kept constant and there are no gravity effects, whereas in the second case we use the Boussinesq approximation for the air properties and including gravity effects.…”

Section: Mesh Studymentioning

confidence: 99%

“…Since the velocity and the temperature are set to be uniformed at the inlet of the computational domain, it is considered that the flow is a developing flow. For thermally and hydraulically developing laminar air flow, the results are validated for global Nusselt number using Stephan correlation [21]. The local Nusselt number is represented as followed:…”

Section: Simulation Validationmentioning

confidence: 99%

Effect of rectangular winglet pair roll angle on the heat transfer enhancement in laminar channel flow

Khanjian

Habchi

Russeil

et al. 2017

International Journal of Thermal Sciences

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Convective heat transfer enhancement can be achieved by generating secondary flow structures that are added to the main flow to intensify the fluid exchange between hot and cold regions in the system. One method involves the use of vortex generators to produce streamwise and transverse vortices on the top of the main flow. This study presents numerical computation results on laminar convection heat transfer in a rectangular channel which bottom wall is equipped with rectangular winglet pair vortex generators. The governing equations are solved using finite volume method by considering steady state, laminar regime and incompressible fluid. Three dimensional numerical simulations are performed to study the effect of the generators' roll-angle b on the flow and heat transfer characteristics. Different values of rollangle b in the range [20 e90 ] are considered, while maintaining a constant angle of attack (a ¼ 30) for all the cases. The influence of the Reynolds number is also studied for values 456 and 911 (based on the channel hydraulic diameter). Both local and global analyses of the thermal performances are carried out using parameters such as the Nusselt number and the friction coefficient. In addition, the position and strength of the longitudinal vortices created are presented and discussed, highlighting their effect on the heat transfer rates throughout the duct, for the various generators' roll-angles. Finally, from both local and global investigations, it is found that the optimal values of the roll-angle, determined for each Reynolds number, are not necessarily 90 , which corresponds to the widely used configuration in the open literature.

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“…Lin et al [20] proposed fins, embedded with wave type vortex generators and predicted an 18-20% fin area reduction by implementation of enhanced fins. Semidimples, full dimples [21,22] wavy up, wavy down [23], inclined projected winglet pair (IPWP) [24] and curved winglets [25,26] are some non-conventional type VGs which have been implemented to get higher thermal hydraulic performance.…”

Section: Introductionmentioning

confidence: 99%

Numerical investigation to predict optimum attack angle combination of longitudinal vortex generators in compact heat exchangers for thermo-hydraulic heightened performance

2019

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The current 3-D numerical analysis explores the effect of combinations of rectangular winglet pairs (RWPs) having different attack angles (i.e. 5°, 15°and 25°) along a row of the tube array, on the performance of the fin and tube heat exchanger (FTHE). The considered airside Reynolds number Re ranges from 500 to 900. In total, six combinations of three attack angle vortex generators (VGs) have been numerically analysed namely 5°-15°-25°, 5°-25°-15°, 15°-5°-25°, 15°-25°-5°, 25°-5°-15°and 25°-15°-5°. The performance of the FTHE is represented by area goodness factor. The performance rankings of the FTHEs are also obtained by the MOORA method. Finally, 5°-25°-15°case provides the best thermal hydraulic performance for which heat transfer coefficient (h) is increased by 68.20% at Re = 500 and 81.78% at Re = 900, with a significant pressure drop penalty.

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Numerical simulation on performances of plane and curved winglet type vortex generator pairs with punched holes

Cited by 112 publications

References 28 publications

On the Heat Transfer Enhancement of Plate Fin Heat Exchanger

On the Heat Transfer Enhancement of Plate Fin Heat Exchanger

Effect of rectangular winglet pair roll angle on the heat transfer enhancement in laminar channel flow

Numerical investigation to predict optimum attack angle combination of longitudinal vortex generators in compact heat exchangers for thermo-hydraulic heightened performance

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