Promvonge, Pongjet

Preferred name

Promvonge, Pongjet

Alternative Name

Promvonge, P.

Main Affiliation

School of Engineering

pongjet.pr@kmitl.ac.th

Now showing 1 - 10 of 12

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Numerical simulation of Al2O3-water nanofluid flow and heat transfer in a tube with angled rings
(2014-01-01)
Promvonge, Pongjet
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Sripattanapipat, Somchai
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Jedsadaratanachai, Withada
A numerical investigation has been conducted to examine turbulent flow and heat transfer characteristics in a three-dimensional isothermal tube mounted with 60° angled rings (AR). The ARs with pitch spacing ratio, PR=1.0 and various blockage ratios (BR) ranging from 0.025-0.1 are introduced. The computations are based on a finite volume method and the SIMPLE algorithm has been implemented. The fluid flow and heat transfer characteristics are presented for Reynolds number (Re) ranging from 3000 to 12000. To generate a main counter-vortex pair flow in the tube, ARs at an attack angle of 60° are mounted repeatedly in the tube. Effect of different BRs at a single PR and nanofluid, Al<inf>2</inf>O<inf>3</inf>-water, with volume fractions 1% and 5% on heat transfer and friction loss is investigated. It is apparent that two main vortex flows created by the ARs exist and help to induce impinging flows on the tube wall leading to drastic increase in heat transfer rate over the tube. The increment in the BR gives rise to the increase in the Nusselt number and friction factor. The computational results reveal that the maximum thermal enhancement factor for the AR with BR=0.025 is found to be 1.8 at Re =3000. The results show that nanofluid, Al<inf>2</inf>O<inf>3</inf> -water, can increase the thermal performance when increasing volume fraction to 5%. © (2014) Trans Tech Publications, Switzerland.
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Augmented thermal effectiveness in solar air receiver with flapped curved winglets: Experimental and numerical analysis
(2025-12-01)
Sripattanapipat, Somchai
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Promvonge, Pongjet
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Jayranaiwachira, Nuthvipa
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Promthaisong, Pitak
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Nakhchi, Mahdi Erfanian
Thermal effectiveness was examined on a solar air receiver equipped with a new lengthwise vortex generator, namely a flapped curved winglet (FCW) mounted on the absorber, utilizing experimental and numerical approaches. Two arrays were employed to assemble two FCWs on the absorber at an angle of attack (α = 59.5°). The FCWs' V-tips were orientated upstream (VU-FCW) and downstream (VD-FCW). Air served as the working fluid, entering a constantly heat-fluxed channel at Reynolds numbers (Re) varying from 5280 to 22,510. Three relative winglet pitches (P<inf>R</inf> = P/H = 1.0–2.0), five winglet-mounted flap angles (β = 0° - 90°), and one winglet blockage ratio (b/H=B<inf>R</inf> = 0.6) were among the major factors. According to the findings, lowering P<inf>R</inf> and β greatly enhances the f (friction factor) and Nu (Nusselt number) of the two FCW arrays. The FCW with P<inf>R</inf> = 1.0 and β = 0° has the largest Nu and f values, approximately 8.3 and 77.39 times bigger than the smooth flat channel, as per the test data. The maximal thermal effectiveness factors (TEF) of the VD-FCW and VU-FCW were approximately 2.83 and 2.61, respectively, at comparable β = 45° and P<inf>R</inf> = 1.5. The f and Nu correlations in employing FCW were also provided. A 3D computational analysis employing the realizable k-ε turbulence model was conducted to examine heat transmission and flow patterns, with the corresponding measured data validating the expected results. The numerical and measured data sets yielded consistent results, and the FCW's heat transmission mechanism was also described.
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Heat transfer in solar air duct with multi-V-ribbed absorber and grooved back-plate
(2021-04-01)
Promvonge, Pongjet
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Khanoknaiyakarn, Chitakorn
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Sripattanapipat, Somchai
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Skullong, Sompol
The article presents an experimental study on heat transfer and friction behaviors in a solar air duct fitted with multiple V-shaped ribs on the absorber and delta-grooves on the back plate. Measurements were carried out in the test duct having a cross-section of width, W = 300 mm and height, H = 27 mm. The air flow rate inside the duct was varied to have Reynolds numbers based on the duct hydraulic diameter from about 7000 to 30,000. Two vortex flow devices: rib and groove turbulators, were introduced to generate the vortex flows along the duct. In the test duct, the upper/absorber plate having a constant heat-flux was mounted repeatedly by multiple V-shaped thin ribs with an attack angle (α) of 45° relative to main flow direction while the lower/back plate was grooved periodically in the delta/triangular shape with an attack angle (θ) of 60°. In the present investigation, the geometrical parameters of the ribs included three different rib- to duct-height ratios (e/H = B<inf>R</inf> = 0.108, 0.162 and 0.217) and three rib-pitch to duct-height ratio (P/H = P<inf>R</inf> = 1.0, 1.5 and 2.0). The experimental results have shown that the duct with the V-ribbed absorber at B<inf>R</inf> = 0.217, P<inf>R</inf> = 1 in conjunction with the delta-grooved back plate has the greatest heat transfer and pressure loss. However, the use of the combined devices with P<inf>R</inf> = 1, B<inf>R</inf> = 0.108 leads to the highest thermal performance and also provides greater heat transfer and thermal performance than employing the V-rib or the delta-groove alone.
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Effect of louver-perforated V-type baffles on thermal effectiveness and entropy in round tube
(2025-08-01)
Promvonge, Pongjet
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Sripattanapipat, Somchai
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Suchatawat, Maturose
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Nakhchi, Mahdi Erfanian
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Skullong, Sompol
An experimental investigation was conducted to assess the influence of insertion of a louver-perforated V-type baffle (LVB) vortex generator into a consistent heat-fluxed tube on thermal performance. This study aimed to optimize thermal effectiveness to boost energy savings and reduce the heat exchanger size. The experiments focused on investigating the thermal features, as well as estimating the entropy of turbulent flow at Reynolds numbers (Re) varying between 4750 and 29,290. The LVBs were positioned in two different arrays on a supporting tape during the present experiment: “V-down” and “V-up,” with the V-apex oriented upstream and downstream, respectively, at a fixed attack angle (α = 52°). At one relative baffle height (B<inf>R</inf> = 0.3) and pitch (P<inf>R</inf> = 1.0), the LVBs dealt with six louver flapped angles (θ = 0°, 10°, 20°, 30°, 45°, and 90°) in addition to three louver-hole sizes and locations (θ<inf>1</inf>, θ<inf>2</inf> and θ<inf>12</inf>). Comparative analysis was also conducted on data obtained from the current smooth tube. According to the findings, the louver angle θ<inf>1</inf> = 20°, located on the baffle's trailing end, had the greatest relative Nusselt number (Nu<inf>R</inf>), which was 5.9 times for V-down and 6.38 times for V-up. Furthermore, compared to the V-down and V-up solid baffles (θ = 0°), their friction losses were lessened. The V-up LVB reached its minimum value at θ<inf>1</inf> = 20°, corresponding to the lowest Re. At θ<inf>1</inf> = 20°, the V-up LVB attained its minimum entropy generation (S˙<inf>gen</inf><sup>′</sup>) and maximum reduced entropy factor (S<inf>R</inf>) around 20.3. At a comparable θ<inf>1</inf> = 20°, the maximal thermal effectiveness factor (TEF) of V-down and V-up were approximately 2.39 and 2.59, respectively. The estimation and documentation of correlations were also performed for the parameters under consideration, namely Nu, f, and TEF.
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Thermal effectiveness and entropy-exergy estimation in a tube with punched double V-winglets
(2026-06-01)
Jayranaiwachira, Nuthvipa
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Sripattanapipat, Somchai
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Promvonge, Pongjet
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Erfanian Nakhchi, Mahdi
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Skullong, Sompol
Vortex generators are effective devices for enhancing heat transfer rates in heating or cooling systems with minimal frictional losses via the production of streamwise vortices. This research effort presents the perforated double V-winglet (P-DVW) and looks at how it affects heat transmission and friction when mounted inside a heat exchange tube that is consistently heated for producing multiple vortices whereas its flow is turbulent. Optimizing thermal performance for increased energy savings and maximizing the Nusselt number ( Nu ) to minimize heat exchanger size are the major goals. Thermal characteristics, including generated entropy and exergy efficiency, are explored in depth. A Reynolds number (Re) that varies from 4760 to 29,270 is employed to explore the friction and thermal features of the tube. The P-DVW parameters encompass attack angles of α<inf>2</inf> = 15° and α<inf>1</inf> = 30°, four porosity ratios ( A <inf>h</inf>/ A <inf>w</inf> = 0, 0.0188, 0.0523, and 0.1026), and three pitch ratios, P<inf>R</inf>, (0.75, 1, and 1.25), while maintaining a constant winglet height. At P<inf>R</inf> = 0.75 and A <inf>h</inf>/ A <inf>w</inf> = 0, the P-DVW exhibits peak f and Nu values around 23.83 and 5.31 times bigger than those of the plain tube, accordingly. Further, under the specified conditions, it yields minimal entropy production, while the optimal exergy efficiency is roughly 0.9829. The thermal effectiveness of P-DVW is anticipated to reach its maximum at 2.55 with Nu<inf>R</inf> = 4.54 at A <inf>h</inf>/ A <inf>w</inf> = 0.0523 and P<inf>R</inf> = 0.75 to reveal its actual benefits. Furthermore, the correlations of f , Nu , and TEF were determined for the examined range of values.
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Numerical Heat Transfer Investigation in a Heat Exchanger Tube with Hexagonal Conical-ring Inserts
(2016-11-01)
Sripattanapipat, Somchai
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Tamna, Sombat
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Jayranaiwachira, Nuthvipa
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Promvonge, Pongjet
The hexagonal conical rings (HCR) modified from the typical conical ring (CR) are used as a turbulence promoter for producing the vortex flows to enhance the heat transfer rate in a heat exchanger tube. To reduce the pressure loss, the V-shaped HCR (V-HCR) obtained by cutting both symmetric plane of the cone-tip of HCR at 30°, 45°and 60°is offered in the present work. The tube fitted with V-HCR elements having a fixed inlet and outlet diameter is numerically investigated. The computation is carried out for Reynolds number in a range of 3000 to 20,000 in a uniform heat-fluxed test tube. The numerical results show that the V-HCR insert leads to much higher heat transfer than the typical CR/HCR insert or the smooth tube alone and also provides lower friction factor. The 30°V-shaped HCR gives the highest heat transfer and thermal performance due to the lowest friction loss, indicating the promising device of the V-HCR.
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Enhanced thermal performance in solar receiver duct with louver-punched V-type winglets: Numerical and experimental study
(2025-03-01)
Suchatawat, Maturose
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Sripattanapipat, Somchai
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Promthaisong, Pitak
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Skullong, Sompol
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Promvonge, Pongjet
An experimental and computational research was performed to explore the augmentation of turbulent convection in a solar receiver channel by utilizing louver-punched V-type winglets (LPVWs) that were fixed to the absorber plate. The simulation utilized the realizable k-ε turbulent model, and the predicated outputs were verified by the relevant measured data. At a fixed attack angle (α) of 45°, the LPVW components were mounted on the absorber with the V-tip facing downstream. Using the LPVW, the newly developed absorber is intended to boost thermal performance by generating multiple flows of longitudinal vortices that induce impinging air streams onto the absorber, thereby enhancing heat transmission. The louvered hole on the winglet serves to reduce pressure loss while preserving the primary vortices. In the current investigation, the winglet parameters consisted of a single relative winglet height (B<inf>R</inf> = 0.4), four louver size ratios (R<inf>L</inf> = e<inf>1</inf>/b = 0.9, 0.7, 0.5, and 0.3), and five louver-flapped angles (β = 90°, 60°, 45°, 30°, and 0°). The LPVW with β > 0° substantially reduced the solid-winglet (β = 0°) friction loss, whereas the heat transmission was slightly declined, as indicated by the results. The solid winglet (β = 0°) exhibited the largest frictional loss and heat transmission, with values approximately 6.3 and 48.2 times the smooth flat duct, respectively. The optimal performance of the LPVW was roughly 2.58, at R<inf>L</inf> = 0.9 and β = 45° Furthermore, empirical correlations for heat transmission and frictional loss were established for this solar receiver duct system. To investigate the heat transmission and flow patterns, a 3-dimensional numerical simulation was implemented, and the predictions were verified against the measured data. The findings were in good accord between the numerical and measured data. For greater thermal performance, the LPVW is reconfigured by altering the locations of the louver holes. The revised LPVW exhibits a peak TEF of 2.7 at β = 35°, l<inf>2</inf>/l<inf>1</inf> = 0.15, l<inf>3</inf>/l<inf>1</inf> = -0.15 and R<inf>L</inf> = 0.9, about 4.65 % superior than the initial analysis.
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Numerical analysis of laminar heat transfer in a channel with diamond-shaped baffles
(2009-01-01)
Sripattanapipat, Somchai
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Promvonge, Pongjet
Laminar periodic flow and heat transfer in a two dimensional horizontal channel with isothermal walls and with staggered diamond-shaped baffles is investigated numerically. The computations are based on the finite volume method, and the SIMPLE algorithm has been implemented. The fluid flow and heat transfer characteristics are presented for Reynolds numbers based on the hydraulic diameter of the channel ranging from 100 to 600. Effects of different baffle tip angles on heat transfer and pressure loss in the channel are studied and the results of the diamond baffle are also compared with those of the flat baffle. It is observed that apart from the rise of Reynolds number, the reduction of the baffle angle leads to an increase in the Nusselt number and friction factor. The computational results reveal that optimum thermal performance is at the baffle angle of 5° for baffle height and spacing of 0.5 and 1 times of the channel height, respectively. The thermal performance of the 5°-10°diamond baffle is found to be higher than that of the flat baffle for all Reynolds numbers used. © 2008 Elsevier Ltd. All rights reserved.
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Experimental and numerical evaluations of thermal performance in heat exchange channel with punched V-type delta-winglets
(2026-09-01)
Promthaisong, Pitak
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Sripattanapipat, Somchai
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Suchatawat, Maturose
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Nakhchi, Mahdi Erfanian
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Promvonge, Pongjet
An experimental examination on the heat transmission improvement of a heat exchange channel (HXC) with punched V-shaped delta-winglets (PVDWs) positioned at regular intervals along the heated wall is presented in the article. This channel has a consistent heat flux for the fluid flow with a Reynolds number (Re) between 5295 and 22,700. By producing vortex flows, the PVDWs help to mix the airflow more rapidly, decrease friction loss via the winglets' louver flap, and direct air jets onto the hot-plate wall. PVDWs with three relative pitches (P<inf>R</inf> = 1, 1.5, and 2) and five louver flap angles (θ = 90°, 60°, 45°, 30°, and 0°) were spaced regularly on the heated surface. The relative winglet height (B<inf>R</inf>) was maintained at 0.5 and the attack angle was fixed at 45°. Two types of winglet patterns were in use: inline PVDW and staggered PVDW. Thermal effectiveness factor (TEF), Nusselt number (Nu), and friction factor (f) were all influenced by the PVDW parameters. Varieties of θ and P<inf>R</inf> are examined parametrically. The smallest Reynolds number results in the greatest rise in frictional factor (f<inf>R</inf> = 75.07), while the largest Reynolds number gives the greatest improvement in heat transfer rate (Nu<inf>R</inf> = 7.63) for I-PVDW at θ = 0° and P<inf>R</inf> = 1.0. Both the S-PVDW and the I-PVDW reached their maximum TEFs at θ = 45° and P<inf>R</inf> = 1, with the former reaching 2.67 and the latter 2.63. Nu and f correlations can also be estimated using their measured data. The best thermal effectiveness and lower friction in the test channel are achieved by using S-PVDWs. The predicted findings were validated by the matching measured data after a 3D numerical study was performed to analyze heat transfer and flow patterns using the realizable k-ε turbulence model. Both the experimental and computational results were in good agreement, and the heat transfer mechanism of the PVDW was elucidated. A reconfiguration of the S-PVDW is performed by reversing the flap angle to increase thermal effectiveness. At θ = −45° and P<inf>R</inf> = 1, the updated S-PVDW shows a highest TEF of 2.78, which is approximately 4% better than the previous analysis.
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Thermal effectiveness augmentation in heated tube with louver-punched delta winglets
(2025-09-01)
Promvonge, Pongjet
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Sripattanapipat, Somchai
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Promthaisong, Pitak
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Suchatawat, Maturose
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Nakhchi, Mahdi Erfanian
Louver-punched delta winglet (LPDW) vortex generators were presented as a way to increase convective heat transmission in a tubular exchanger. LPDW arrays were categorized as inline or staggered louver-punched delta winglets (I-LPDW and S-LPDW, respectively). Experimental and numerical research was carried out for Reynolds numbers varying from 4760 to 29,290 to analyze the thermal patterns and flow characteristics within a constant heat flux tube with LPDWs. The turbulence model adopted for the present research was the realizable k-ε model. For both I-LPDW and S-LPDW winglet arrangements, a single ratio of blockage (B<inf>R</inf> = e/D = 0.25), pitch ratio (P<inf>R</inf> = P/D = 1), and attack angle (α = 60°) was utilized as well as three ratios of louver length (L<inf>R</inf> = d/e = 0.24–0.56) and five flap angles (θ = 0°–90°). The research showed that when the θ and L<inf>R</inf> values fall, the LPDW's friction factor (f) and Nusselt number (Nu) grow since streamwise vortices that possess greater kinetic energy of turbulence promote fluid mixing. The winglet with θ = 45°, L<inf>R</inf> = 0.24 exhibited a peak TEF of 2.56 for I-LPDW and 2.63 for S-LPDW whereas the winglet with θ or L<inf>R</inf> = 0° had the largest Nu and f values, at 5.41 and 24.38 times, respectively. The numerical results illustrated that both LPDWs produce many longitudinal vortices throughout the tube. These flow patterns improved fluid mixing in the tube by raising the fluid's kinetic energy of turbulence. Additionally, the findings of the verification between the computational and experimental data were satisfactory. The Nu and f correlations for the I-LPDW and S-LPDW were also established using measured data.

Promvonge, Pongjet

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