Promvonge, Pongjet

Preferred name

Promvonge, Pongjet

Alternative Name

Promvonge, P.

Main Affiliation

School of Engineering

pongjet.pr@kmitl.ac.th

Now showing 1 - 4 of 4

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
Enhanced thermal performance in solar receiver duct with louver-punched V-type winglets: Numerical and experimental study
(2025-03-01)
Suchatawat, Maturose
;
Sripattanapipat, Somchai
;
Promthaisong, Pitak
;
Skullong, Sompol
;
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.
Some of the metrics are blocked by your
consent settings
Thermal effectiveness augmentation in heated tube with louver-punched delta winglets
(2025-09-01)
Promvonge, Pongjet
;
Sripattanapipat, Somchai
;
Promthaisong, Pitak
;
Suchatawat, Maturose
;
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.
Some of the metrics are blocked by your
consent settings
Numerical Heat Transfer Study of Turbulent Tube Flow through Winglet-pairs
(2016-11-01)
Tamna, Sombat
;
Sripattanapipat, Somchai
;
Promvonge, Pongjet
A numerical investigation on heat transfer behaviors in a constant heat-fluxed round tube inserted with winglet vortex generators is conducted. Air as the working medium flows through the tube for Reynolds numbers (Re) between 4000 and 20,000. The effect of using the rectangular-winglet tape (RWT) on heat transfer characteristics in the tube is numerically examined. For comparison purpose, the trapezoidal-winglet tape (TWT) and delta-winglet tape (DWT) are also offered. The RWT parameters in this work include four relative winglet-to-tube heights or blockage ratios (B<inf>R</inf>=b/D= 0.1, 0.15, 0.2, and 0.25) while the TWT and DWT are only at B<inf>R</inf>= 0.2. All the winglet pairs are at a single attack angle (α= 45°) and pitch ratio (p/D=P<inf>R</inf>=4). The numerical results show that the Nusselt number (Nu) and friction factor (f) of the tube inserts are enhanced with increasing B<inf>R</inf> values. The Nu for the inserted tube is about 1.8-2.7 times above that for the smooth tube while the f is around 4.5-11 times higher. For the studied B<inf>R</inf> ranges, the highest thermal performance is 1.48 for the RWT with B<inf>R</inf>= 0.1 at lower Reynolds number.

Promvonge, Pongjet

Filters

Settings

Sort By

Results per page