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 41

Some of the metrics are blocked by your
consent settings
Numerical heat transfer study of square duct equipped with novel flapped V-baffles
(2024-03-01)
Thianpong, Chinaruk
;
Promvonge, Pongjet
;
Skullong, Sompol
;
Promthaisong, Pitak
;
Nakhchi, Mahdi Erfanian
The paper describes a computational study of heat transfer enhancement inside a square duct with V-shaped flapped baffles located repeatedly on the bottom and top walls for fluid flowing with Reynolds numbers (Re) from 3000 to 21,000. The basic goal of this work is to attain the largest relative Nusselt number (Nu/Nu<inf>0</inf>) whilst maintaining the highest thermal performance to improve energy savings. A finite volume method was used in the computations, along with the Realizable k‒ε turbulent model. The variable baffle parameters considered first in the current simulation were the relative height/blockade ratio (B<inf>R</inf> = 0.05−0.2) and the flap angle of the baffle hole (β = 0° − 90°), while the fixed parameters included the attack angle (α = 60°), hole diameter ratio (d<inf>R</inf> = 0.5), and pitch ratio (P<inf>R</inf> = 0.5). To accomplish this goal, the previously mentioned parameters providing the best thermal performance were investigated further by extending the values of B<inf>R</inf> to 0.25−0.3, d<inf>R</inf> to 0.8 and α to 45°−30°. The simulation results indicate that the jet flowing from the flapped hole, as well as the vortices created by the baffle, can boost heat transfer and friction loss in comparison to the plain duct. In comparison, using a flapped baffle with β > 0° results in less friction loss, a greater thermal enhancement factor (TEF), and a higher Nusselt number than using a baffle with no flap. The first investigation disclosed that for B<inf>R</inf> = 0.2 and β = 20°, the greatest TEF of 2.19 with Nu/Nu<inf>0</inf> of 7.9 times are obtained. The extended study, on the other hand, showed that the highest TEF of roughly 2.49 with Nu/Nu<inf>0</inf> of 8.4 times are seen for α = 45°, d<inf>R</inf> = 0.8, B<inf>R</inf> = 0.25 and β = 20° at lowest Re. Thus, the flapped baffle provides a significant increase in Nu/Nu<inf>0</inf> and TEF over the baffle alone.
Some of the metrics are blocked by your
consent settings
Augmented thermal effectiveness in solar air receiver with flapped curved winglets: Experimental and numerical analysis
(2025-12-01)
Sripattanapipat, Somchai
;
Promvonge, Pongjet
;
Jayranaiwachira, Nuthvipa
;
Promthaisong, Pitak
;
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.
Some of the metrics are blocked by your
consent settings
Analysis of exergy and heat transfer in a tube fitted with flapped V-baffles
(2024-07-01)
Jayranaiwachira, Nuthvipa
;
Promvonge, Pongjet
;
Tongyote, Paritkavin
;
Skullong, Sompol
;
Nakhchi, Mahdi Erfanian
Vortex generator is a device that shows promise in generating streamwise vortices that can be utilized for boosting the rate of heat transmission inside a cooling/heating system with a relatively smaller penalty in terms of friction loss. The primary goal of the current research is to maximize the comparative Nusselt number ratio (Nu/Nu<inf>0</inf>) to be as large as possible to lower the size of the system while keeping thermal performance as high as feasible to save more energy. Thus, in the current study, the impacts of inserting the flapped V-baffle vortex generator (FBVG) on the thermal effectiveness improvement of a round tube were experimentally investigated. At a fixed attack angle (α = 60°) and baffle blockage ratio (B<inf>R</inf> = b/D = 0.3), the geometrical behaviors of FBVGs placed periodically along two edges of a straight tape were six different flap angles (θ = 0°, 25°, 35°, 45°, 65° and 90°) and three ratios of baffle pitches (P/D = P<inf>R</inf> = 2.0, 1.5, and 1.0). The current V-baffles, which were positioned on both tape edges, were designed to reduce friction loss caused by interrupting the central core flow when placed on both tape sides. The measurement results focused on the friction loss and thermal behaviors, including exergy and entropy analyses for Reynolds number from 4750 to 29,270. In the findings, the Nusselt number and friction factor of FBVG at θ = 0° and P<inf>R</inf> = 1 are, respectively, up to 5.6 and 35.24 times larger than those of the smooth tube. The entropy generation (S˙<inf>gen</inf>′) seems to decline as θ and P<inf>R</inf> increase, with the smallest S˙<inf>gen</inf>′ found at θ = 0° and P<inf>R</inf> = 1 for lower Re. The FBVG has the greatest exergy efficiency (η<inf>Ex</inf>) at θ = 0° and P<inf>R</inf> = 1. To find the true benefits of FBVG, its thermal performance is estimated and seen to reach a maximum at about 2.44 with Nu<inf>R</inf> = 4.65 at θ = 45° and P<inf>R</inf> = 1. The optimal scenario at θ = 25° and P<inf>R</inf> = 1 was preferred, however, since it yielded the largest Nu<inf>R</inf> = 5.42 at TEF = 2.39.
Some of the metrics are blocked by your
consent settings
Entropy generation and thermal performance of tubular heat exchanger fitted with louvered corner-curved V-baffles
(2023-02-01)
Jayranaiwachira, Nuthvipa
;
Promvonge, Pongjet
;
Thianpong, Chinaruk
;
Skullong, Sompol
The current article deals with an experimental study on entropy generation analysis and thermohydraulic performance of a uniform heat-flux tube equipped with louvered corner-curved baffle tape (LCBT). Air was drawn into the inserted tube for the Reynolds number (Re) between 4760 and 29,300. The V-shaped LCBT arranged by V-tip in downstream direction was introduced with three baffle pitch ratios (P<inf>R</inf> = 1–2) and six louver angles (θ = 0–90°) for a fixed attack angle (α) of 30° and baffle height ratio (B<inf>R</inf> = 0.25). The impacts of investigated parameters on the thermal enhancement factor (TEF), Nusselt number (Nu), friction factor (f), and total entropy generation (S˙<inf>gen</inf>′) were examined. The measurements showed that the LCBT with the smallest values of P<inf>R</inf> = 1, θ = 0° give the largest Nu and f at about 4.4 and 19.2 times above the plain tube values, respectively. However, the greatest TEF around 2.23 was seen for employing the LCBT at P<inf>R</inf> = 1, θ = 45°. The entropy analysis also showed that the S˙<inf>gen</inf>′ is found to decline with the increment of P<inf>R</inf> and θ, whereas the minimal S˙<inf>gen</inf>′is at P<inf>R</inf> = 1, θ = 0° for lower Re but at P<inf>R</inf> = 1, θ = 45° for higher Re. Furthermore, the Nu and f empirical correlations for employing LCBTs were also proposed.
Some of the metrics are blocked by your
consent settings
Heat transfer in solar air duct with multi-V-ribbed absorber and grooved back-plate
(2021-04-01)
Promvonge, Pongjet
;
Khanoknaiyakarn, Chitakorn
;
Sripattanapipat, Somchai
;
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.
Some of the metrics are blocked by your
consent settings
Thermohydraulic performance and entropy generation in heat exchanger tube with louvered winglet tapes
(2022-11-01)
Promvonge, Pongjet
;
Skullong, Sompol
The present article concerns with thermohydraulic performance, flow friction and entropy generation analysis in a heated tube contained with louvered winglet tape (LWT). The experiment was conducted in a uniform heat-fluxed test tube for turbulent fluid flow, Reynolds number (Re) ranging from 4760 to 29,260. The purpose of the LWT insert is to produce streamwise vortices assisting to induce impinging-jets onto the tube wall and to decline the pressure loss through the louver mounted on the winglet aside from providing rapid mixing of fluid flow. In the present experiment, the louvered winglets were mounted periodically on a double-sided straight tape with six different louver angles (θ = 0 ˗ 90°) and three winglet pitch ratios (P<inf>R</inf> = 1 ˗ 2) at a single relative winglet height (B<inf>R</inf> = 0.25) and a fixed attack angle (α) of 30°. There were two-types of LWT arrangements: inline and staggered louvered-winglet tapes (I-LWT and S-LWT). To examine the optimum thermohydraulic performance, an influence of θ at each P<inf>R</inf> on the rate of heat transfer and friction loss inside the tube was explored. The measured results disclosed that the Nusselt number (Nu) and friction factor (f) from using both types of LWTs rise considerably with the reduction of P<inf>R</inf> and θ. The entropy generation (S˙<inf>gen</inf>') was declined with the decrease in Re, P<inf>R</inf> and θ where the minimum S˙<inf>gen</inf>' was obtained for the I-LWT tube at P<inf>R</inf> = 1, θ = 0° and lowest Re. The peak thermal enhancement factors (TEF) of the S-LWT and the I-LWT were, respectively, around 2.22 and 2.18 at similar P<inf>R</inf> = 1, θ = 45°. The Nu, f and TEF correlations for using LWT insert were also reported.
Some of the metrics are blocked by your
consent settings
Enhanced thermal effectiveness of square duct with V-type double-baffles: Numerical study
(2024-09-01)
Promvonge, Pongjet
;
Sripattanapipat, Somchai
;
Thianpong, Chinaruk
;
Skullong, Sompol
;
Promthaisong, Pitak
The article puts forward three-dimensional computational research on heat transmission augmentation within a square channel containing 45o V-type double-baffles positioned on the lower and top parts at regular intervals in the turbulence zone for Reynolds numbers (Re) that vary from 3000 to 20,000. The primary goal of this research is to increase the thermal effectiveness and relative Nusselt number (Nu/Nu<inf>0</inf>), in order to conserve energy and reduce the size of the heating or cooling system. The simulations utilize a finite volume approach in common with the SIMPLE algorithm, whereas the turbulent model used is the realizable k–ε. The baffles are designed to be separated vertically for reducing pressure loss. Both single V-baffles and double V-baffles have four relative pitches (PR = 0.4, 0.5, 0.6, and 1.0) and height/blockage ratios (BR = 0.05, 0.1, 0.15, and 0.2), with a fixed attack angle (α) of 45o. The computational findings show that both V-baffles are capable of producing the primary vortices, but only the double V-baffles have the ability to provide the impinging streams onto the wall, cooling the region behind the baffles. This suggests that the double V-baffles not only boost heat transmission but also reduce frictional loss. When compared to a single V-baffle, the double ones enhance heat transfer by an average of 1.04–9.94% while decreasing frictional loss by an average of 9.88–31.73%. The thermal effectiveness factor (TEF) of the double V-baffles ranges from 1.03 to 3.21, and its peak value of around 3.21 is for PR = 0.4, BR = 0.05, at lower Re.
Some of the metrics are blocked by your
consent settings
Effect of arc-shaped twisted-baffles on augmented heat transfer in a rectangular duct
(2023-02-01)
Promvonge, Pongjet
;
Phila, Arnut
;
Chuwattanakul, Varesa
;
Chokphoemphun, Suriya
;
Eiamsa-Ard, Smith
In this current work, the effect of utilizing arc-shaped twisted-baffles (T-ABs) in a rectangular air channel on thermal performance factor (TPF) has been experimentally studied. In these experiments, the influence of the changes in parameters such as dimensions of pitch ratio (p/w), attached arc-shape angle (α), and Reynolds number (Re) are explored. The comparisons demonstrate that a channel mounted with arc-shaped twisted-baffles yielded considerably greater Nusselt numbers than a smooth channel, possibly attributable to multiple-impinging jets near the channel surface. Heat transfer enhancements of twisted arc-shaped baffles (T-AB) having larger attack angles were superior to those having smaller attack angles. The one with α = 90o offered greater heat transfer rates than the ones with α = 20o, 40o, 60o, and 80o by approximately 8%, 7%, 4%, and 2%, respectively. The superior heat transfer was attributed to the better contact between the working fluid and heat transfer surfaces. In addition, utilizing arc-shaped twisted-baffles with the lowest p/w of 4.0, in a channel produced stronger vortices and multiple impinging jets, which caused better fluid mixing than other p/w. The optimum condition is achieved using T-ABs at an attached arc-shape angle of α = 90o, p/w = 4.0 and Re = 4000, where the heat transfer rate (Nu), friction factor (f) and TPF are found to be, respectively, 3.31, 4.68 and 1.98 times greater than those of a plain channel.
Some of the metrics are blocked by your
consent settings
Thermal characteristics in solar air duct with V-shaped flapped-baffles and chamfered-grooves
(2021-06-01)
Promvonge, Pongjet
;
Skullong, Sompol
The article deals with augmenting the thermohydraulic performance of a solar heat exchanger duct with combined V-shaped baffle-and-groove vortex generators (VGs). Heat transfer behaviors from the combined VGs mounted in the duct absorber were investigated experimentally. Two VGs mounted on the absorber plate, the V-shaped flapped-baffle and chamfered-groove with a similar attack angle, α = 45°, were arranged by two arrays: V-apex pointing upstream (VU) and pointing downstream (VD). The vital purpose of using the flapped-wing mounted on the baffle (called “flapped baffle”) is to decline the pressure loss from the baffle without deterioration of the main vortices behind. The present experiment was carried out to encompass Reynolds number (Re) in a range of 5290 to 22,600, using air as a working fluid. The pertinent parameters of grooves were three groove pitch ratios (P<inf>R</inf> = 1.0, 1.5 and 2.0) while the baffle characteristics included four flap angles of the flap mounted on the baffle central area (β = 30°, 45°, 60° and 90°), three relative baffle pitches (P<inf>R</inf> = 1.0, 1.5 and 2.0) at one baffle height. Effects of the baffle and groove parameters as stated above on Nusselt number (Nu), friction factor (f) and thermal enhancement factor (TEF) were examined. The experimental results have revealed that the use of flapped-baffle and groove VG devices at P<inf>R</inf> =1.0 and β = 30° gives the largest f and Nu, especially for the VU case owing to strongly impinging jets issuing from the flap opening on the absorber surface area behind the baffle. Specifically, the maximum TEF is found to be 2.68 for the combined VU devices with P<inf>R</inf>=1.5, β = 45° and Re=5290. With these measured data, the Nu and f correlations are also determined.
Some of the metrics are blocked by your
consent settings
Enhanced thermal performance in tubular heat exchanger contained with V-shaped baffles
(2021-02-25)
Promvonge, Pongjet
;
Skullong, Sompol
The vortex-flow device is a promising streamwise vortex generator employed to produce the counter-rotating vortices along a heated tube to augment the heat transfer rate with comparatively smaller friction loss penalty. Thus, the influences of V-shaped baffle vortex generator (hereafter called “V-baffle”) insert in a heated tube on thermal-performance enhancement were experimentally examined in the current work. The geometric characteristics of the V-baffles mounted repeatedly on the edges of a flat plate/tape were three ratios of relative baffle blockages, (b/D = B<inf>R</inf> = 0.1, 0.15 and 0.2), and four ratios of baffle pitches, (P/D = P<inf>R</inf> = 0.5, 1.0, 1.5 and 2.0) at a fixed angle of attack (α = 30°). The present V-baffle placed on the tape edge was aimed to lessen the pressure loss from disturbing the central core flow for the case of placing it on the double sides of a tape as found in the literature. The experiment was conducted by letting air flow through the test tube with Reynolds number (Re) in the range of 4192 to 25,750. The current study indicated that the friction factor and heat transfer using the V-baffle inserts increase considerably with rising B<inf>R</inf> but reducing P<inf>R</inf>. The V-baffle with B<inf>R</inf> = 0.2, P<inf>R</inf> = 0.5 provides the highest friction factor and rate of heat transfer at about 18.25 and 4.46 times above the plain tube, respectively. A new modified thermal enhancement factor (TEF) is offered and found that its peak for each case appearing at the lowest Re, is in a range of 2.14–2.34 where the optimum TEF of 2.34 is visible at P<inf>R</inf> = 1.0, B<inf>R</inf> = 0.15. Furthermore, correlations of Nusselt number and friction factor for the present V-baffles are determined. TEF of the current device is found to be superior to that of other enhanced devices in comparison.

Promvonge, Pongjet

Filters

Settings

Sort By

Results per page