Mixed convection heat transfer from a triangular cylinder subjected to upward cross flow

Altaç, Zekeri̇ya; Sert, Zerrin; Mahír, Necati; Timuralp, Çisil

doi:10.1016/j.ijthermalsci.2018.11.010

“…(1) Dual branches depend on a certain range of λ (2) ere occur triple ranges of solution, no branch solution exists when λ > λ c , two branches occur when 0.23 ≤ λ ≤ λ c , and a single branch exists when λ > 0.23 (3) e heat transfer improved due to the volume fraction of Cu in a hybrid nanofluid (4) In the thermal radiation presence, the dual behavior is noted in the rate of heat transfer in both branches (5)…”

Section: Discussionmentioning

confidence: 99%

“…Moreover, the nonuniqueness of the solutions was noticed. Recently, Altaç et al [5] studied the mixed convection flow subjected to upward cross flow. Many other significant cross-flow studies can be obtained in these reported research papers [6][7][8][9][10].…”

Section: Introductionmentioning

confidence: 99%

Numerical Analysis of $Cu + {Al}_{2}$

Dero

¹

,

Lund

²

,

Shah³

et al. 2021

Mathematical Problems in Engineering

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The motion of water conveying copper and aluminum nanoparticles on a heated moving sheet when thermal radiation and stretching/shrinking surface is significant and is investigated in this study to announce the increasing effects of volume fractions, thermal radiation, and moving parameters on this transport phenomenon. Furthermore, the flow of a Cu − Al 2 O 3 /water hybrid nanofluid across a heated moving sheet has been studied in both cross and streamwise directions. Thermal radiation effect is also considered, as this effect along with cross flow has not yet been investigated for the hybrid nanofluid in the published literature. Two distinct types of nanoparticles, namely, Al 2 O 3 (alumina) and Cu (copper), have been used to prepare hybrid nanofluid where water is considered as a base fluid. The system of nonlinear partial differential equations (PDEs) has been transferred to ordinary differential equations (ODEs) by compatible transformations before solving them by employing the III-stage Lobatto-IIIa method in bvp4c solver in MATLAB 2017 software. Temporal stability analysis has been carried out in order to verify stable branch between two branches by obtaining the smallest eigenvalue values. The branches obtained are addressed in depth against every applied parameter using figures and tables. The results show that there are three ranges of branches, no solution exists when λ > λ c , dual branches exist when 0.23 ≤ λ ≤ λ c , and a single solution exists when λ > 0.23 . Moreover, thermal layer thickness declines initially and then enhances in the upper and lower solutions for the higher values of the thermal radiation parameter.

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“…Germanium material was used as the solar cell, while aluminium was used as the cooling pad material. A combination of the laminar model corresponding to a Reynolds number (Re) of 1482.41 at 0.5 L/m and an enhanced wall function K-ε model corresponding to 1-2.5 L/m with an increase in Re from 1482.41 to 8372.26 was used and adapted, as described in [97][98][99][100][101]. A 10 −6 residual was considered to indicate a converged solution.…”

Section: Novel Approach To Cpv Coolingmentioning

confidence: 99%

Cooling of Concentrated Photovoltaic Cells—A Review and the Perspective of Pulsating Flow Cooling

Ibrahim

¹

,

Luk

²

,

Luo

³

2023

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This article presents a review to provide up-to-date research findings on concentrated photovoltaic (CPV) cooling, explore the key challenges and opportunities, and discuss the limitations. In addition, it provides a vision of a possible future trend and a glimpse of a promising novel approach to CPV cooling based on pulsating flow, in contrast to existing cooling methods. Non-concentrated photovoltaics (PV) have modest efficiency of up to around 20% because they utilise only a narrow spectrum of solar irradiation for electricity conversion. Therefore, recent advances employed multi-junction PV or CPV to widen the irradiation spectrum for conversion. CPV systems concentrate solar irradiation on the cell’s surface, producing high solar flux and temperature. The efficient cooling of CPV cells is critical to avoid thermal degradation and ensure optimal performance. Studies have shown that pulsating flow can enhance heat transfer in various engineering applications. The advantage of pulsating flow over steady flow is that it can create additional turbulence and mixing in the fluid, resulting in a higher heat transfer coefficient. Simulation results with experimental validation demonstrate the enhancement of this new cooling approach for future CPV systems. The use of pulsating flow in CPV cooling has shown promising results in improving heat transfer and reducing temperature gradients.

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“…The eddy shedding phenomenon behind the cylinder has been extensively studied by the fluid dynamics community because of its importance in engineering applications. Contrary to numerous publications on circular cylinders, it is only recently that research has been conducted on the forced flow over cylinders of different cross-sections (circular (Lupi, 2013;Laidoudi and Bouzit, 2018;Patel and Chhabra, 2019;Barati et al, 2022), square (Mahir and Altaç, 2019;Arif and Hasan, 2020;Sharma and Dutta, 2022), semicircular, elliptic (Zhang et al, 2020;Hyun and SikYoon, 2022;Salimipour and Yazdani, 2022), and trapezoidal). Although non-circular cylinders play a dominant role in many technical applications, there is very limited information in the literature on mixed (natural and force) convection heat transfer and flow over or from noncircular cylinders.…”

Section: Introductionmentioning

confidence: 99%

“…They reported that the amplitude of oscillation of the global flow and heat transfer quantities increased drastically, resulting from rapid mixing behind the obstacle. Altaç et al (2019) investigated mixed convection heat transfer and fluid flow over a long horizontal equilateral triangular cylinder in an unconfined channel. Their simulation variables, Reynolds and Richardson numbers, are varied in the range 10 ≤ Re ≤ 200 and 0 ≤ Ri ≤ 10.…”

Section: Introductionmentioning

confidence: 99%

Combined Forced and Natural Convection From a Single Triangular Cylinder

Sert

2024

Isı Bilimi Ve Tekniği Dergisi

Self Cite

0

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Unsteady laminar confined and unconfined fluid flow and mixed (forced and free) convection heat transfer around equilateral triangular cylinders are investigated numerically. The computation model is a two-dimensional domain with blockage ratios of BR=0.5, 0.25, 0.2, 0.1, 0.05, and 0.0333, with the Reynolds numbers ranging from 100 to 200. The working fluid is water (Pr = 7). The effects of aiding and opposing thermal buoyancy are incorporated into the Navier-Stokes equations using the Boussinesq approximation. The Richardson number, which is a relative measure of free convection, is varied in the range -2 ≤ Ri ≤ 2. The governing equations are solved by using the Finite Volume Method with a second-order upwind scheme used for differencing of the convection terms, and the SIMPLE algorithm is used for the velocity-pressure coupling. A discussion of the effect of the blockage ratio on the mean drag, mean rms lift coefficients, the Strouhal number, and the mean Nusselt number is also presented. The iso-vorticity contours and dimensionless temperature field are generated to interpret and understand the underlying physical mechanisms. The results reveal that, in addition to the Richardson and Reynolds numbers, the blockage rate is effective in the vortex distribution in the channel. It has been determined that the vortices formed behind the cylinder spread to the channel with a decreasing blockage rate. Especially at high Reynolds numbers, both the drag coefficient and the mean Nusselt number are significantly affected by the blockage ratio. For Ri=0, the drag coefficients for BR=0.25 in comparison to the BR=0.05 case are about 9% and 29% larger for Re= 100 and 200, respectively. For BR

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Mixed convection heat transfer from a triangular cylinder subjected to upward cross flow

Cited by 15 publications

References 17 publications

Numerical Analysis of $Cu + {Al}_{2}$

Numerical Analysis of $Cu + {Al}_{2}$

Cooling of Concentrated Photovoltaic Cells—A Review and the Perspective of Pulsating Flow Cooling

Combined Forced and Natural Convection From a Single Triangular Cylinder

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Mixed convection heat transfer from a triangular cylinder subjected to upward cross flow

Cited by 15 publications

References 17 publications

Numerical Analysis of Cu + Al 2

Numerical Analysis of Cu + Al 2

Cooling of Concentrated Photovoltaic Cells—A Review and the Perspective of Pulsating Flow Cooling

Combined Forced and Natural Convection From a Single Triangular Cylinder

Contact Info

Product

Resources

About

Numerical Analysis of $Cu + {Al}_{2}$

Numerical Analysis of $Cu + {Al}_{2}$