Promvonge, Pongjet
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Promvonge, Pongjet
Alternative Name
Promvonge, P.
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pongjet.pr@kmitl.ac.th
43 results
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Item type:Publication, Numerical simulation of Al2O3-water nanofluid flow and heat transfer in a tube with angled rings(2014-01-01); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Heat transfer and flowfriction behaviors in a channel with multiple 30° V-ribs(2014-01-01); The paper presents an experimental study on heat transfer and flow friction characteristics in a rectangular channel fitted with periodically rectangular V-ribs. The multiple V-rib turbulators are tested in the channel having an aspect ratio (width to height ratio), AR=10 and height, H= 30 mm, with three rib-to-channel height ratios (e/H=0.2, 0.3, and 0.4), two rib-pitch to channel-height ratios (PR=P<inf>1</inf>/H= 3 and 4) and a single attack angle (α=30°). The upper plate of channel is uniformly heated at a constant heat-flux. The experiment has been conducted by varying airflow velocity in order to obtain the Reynolds number range from 5000 to 24,000. The experimental results show a significant effect of the presence of the ribs on the heat transfer rate and pressure drop over the smooth channel. The measured data indicates that the V-rib turbulators with e/H = 0.4 and PR =3 yields the highest heat transfer rate and friction loss. All the V-rib turbulators perform much higher than the smooth channel with no rib. © 2014 Asian Institute of Technology. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Numerical thermal performance study in a heat exchanger tube with inclined elliptical rings(2017-06-01); The paper deals with a numerical study on the effect of inclined elliptical ring (IER) on heat transfer augmentation in a uniform heat-fluxed heat exchanger tube. In the present work, the 60° IER was mounted repeatedly in the tube with six different eccentricity ratios (E<inf>R</inf> = b/a = 1, 0.9, 0.8, 0.7, 0.6 and 0.5) at a single ring-pitch ratio P<inf>R</inf> = 1.0. Air as the test fluid flows into the tube for Reynolds number ranging from 4000 to 20,000. To find the optimum thermal performance, the effect of E<inf>R</inf> values on the heat transfer and pressure loss is investigated. The study indicates that the use of IER can induce higher turbulent intensity imparted to the flow leading to higher heat transfer in range of about 237 to 461% above the smooth tube. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Thermal characteristics in turbulent channel flows with V-baffle vortex generators(2014-01-01); ; Eiamsa-Ard, S.Experimental work has been performed to examine the effects of V-baffle vortex generators on the heat transfer and friction characteristics in a channel under a constant heat flux boundary condition. In the experiments, V-baffles at different pitch ratios (PR=P/e = 4.0, 6.0 and 8.0) were carried out. Measurements were carried out for a channel of one aspect ratio, AR = W/H = 4.0 and duct height, H= 40 mm with baffle height, e = 8 mm. Experiments were conducted for the Reynolds number range of 6000 to 22,000. The distributions of temperature and local Nusselt number on bottom channel wall were observed with thermochromic liquid crystal (TLC) sheet. Isothermal friction factors were also taken and presented. The obtained results demonstrate that heat transfer increases with the increase of Reynolds number, whereas friction factor (f) shows the opposite trend. Experimental results also show that the channels with V-baffle at the highest pitch ratio (PR = 8.0) provide highest heat transfer than others. © 2014 Asian Institute of Technology. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Experimental study of combustion characteristics in a rice husk fired vortex combustor(2001-12-01); Silapabanleng, KulthornThis paper presents the study of combustion characteristics of rice husk fuel in an annular vortex combustor (VC). The temperature distributions for selected locations inside the combustor and the fly ash and smoke from its flue gas were measured and observed respectively. Measurements were made by setting a constant mass flow rate of rice husk to be 0.2 kg/min and by varying the equivalence ratio, φ, to be 0.8, 1.0 and 1.2. To study the effect of feeding secondary air on flame stability, three values of the ratio of volumetric flow rates of the secondary air to the total air, (λ), were used and set to be 0.0, 0.2 and 0.4. The experiment shows the maximum temperature of about 1000° C in the upper chamber with less smoke of flue gas. Besides, emissions and the sizes of flyash particles from the exhaust stack can be controlled by the flow rate ratios of the secondary air to the total air, λ The VC shows an excellent performance, low emissions, high stabilization and ease of operation in firing the fine rice husk. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Thermal performance enhancement in solar air heater channel with periodically V-shaped baffles(2012-12-01); The research paper presents a study on thermal performance enhancement in a rectangular channel heat exchanger mounted with periodically V-shaped baffles. The channel has an aspect ratio (width to height ratio), AR=10 and height, H=30 mm while baffle characteristics are the baffle to channel height ratio, e/H=0.2, 0.3 and 0.4; the baffle pitch to channel height ratio, PR=P/H=2 and 2.67; the attack angle (α) of 30°relative to the flow direction. The experiment has been conducted by varying air flow velocity in order to adjust Reynolds number range from 5000 to 25,000. The upper wall of the channel is uniformly heated as a constant heat flux while the rests are covered with thermal insulations to reduce heat loss to surroundings. The effects of the baffles on Nusselt number and friction factor have been examined. The overall performance of tested baffled channel is evaluated to obtain the degree of heat transfer enhancement and friction factor induced by baffles with respect to the smooth channel under similar flow conditions. © 2011 IEEE. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Heat transfer improvement in a square duct with diagonal inclined ribs(2014-01-01); ; Limkul, ThitipatThis research presents a numerical study of turbulent periodic flow and heat transfer in three-dimensional isothermal-fluxed square duct with diagonal inclined rib inserted. The fluid flow and heat transfer characteristics are presented for Reynolds numbers in the range of 4000 to 20,000. The computations based on the finite volume method, and the SIMPLE algorithm has been implemented. Effects of rib pitch ratios (0.5 to 2) at a single blockage ratio of 0.2 and attack angle of 60° on heat transfer and friction factor in the duct are examined and their results of the inclined rib are also compared with those of the smooth duct. It is found that the inclined rib provides higher heat transfer rate and friction factor than the smooth duct for all cases. In addition, the decreasing of the pitch ratio leads to the rise in the Nusselt number and friction factor. © (2014) Trans Tech Publications, Switzerland. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Enhancement of heat transfer in a tube with regularly-spaced helical tape swirl generators(2005-01-01) - Some of the metrics are blocked by yourconsent settings
Item type:Publication, 3D simulation on flow behavior and heat transfer in a circular tube with inclined different arrangement of thin rib(2013-01-28); This work deals with periodic flow, friction loss and heat transfer characteristics in a constant temperature-surfaced circular tube fitted with rib vortex generators (RVG). The computations are based on the finite volume method with the SIMPLE algorithm implemented. The fluid flow and heat transfer behaviors are presented for Reynolds numbers ranging from 100 to 1000. To generate two main vortex flows through the tested section, the 45<sup>o</sup> RVGs are mounted repeatedly in in-line arrangements on the top and bottom walls and in the central area of the tested section. Effects of different RVG heights, BR in a range from 0.1D to 0.3D with a single pitch of 1.5D on heat transfer and friction losses in the test section are examined. It is apparent that the vortex flows created by the RVG exist and help to induce periodically impinging flows on a sidewall leading to drastic increase in the heat transfer rate over the test section. The computational results reveal that the optimum thermal performance is about 2.38 for using the RVG height of 0.2D for the RVG placed on the tube walls at the highest Re value. © (2013) Trans Tech Publications, Switzerland. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Turbulent convection in a solar air heater channel with baffles/winglets(2014-01-01)