Chuwattanakul, Varesa
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Preferred name
Chuwattanakul, Varesa
Alternative Name
Chuwattanakul, V.
Main Affiliation
Email
varesa.ch@kmitl.ac.th
12 results
Now showing 1 - 10 of 12
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Item type:Publication, Influences of Spray Drying Conditions on the Physiochemical Properties of Karanda Fruit(2023-01-01); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Effect of a TiO2/Water Nanofluid on the Thermal Cooling of a Central Processing Unit(2024-01-01); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Effect of arc-shaped twisted-baffles on augmented heat transfer in a rectangular duct(2023-02-01); ; - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Temperature Distribution and Combustion Characteristics of Rice Husks in a Fluidized Bed Combustor(2022-01-01); ; ; Saysroy, AnuchaThis article presents an experimental study on the combustion characteristics of rice husks in a fluidized bed combustor (FBC). In the experiments, the FBC was tested with rice husk feeding rates ranging from 10-15.5 kg/hr to yield percent excess air (EA) between 25% and 35%. The axial and radial temperature distribution within the FBC was measured at a selected location while gas emissions were also monitored. From the experimental results, it can be seen that the maximum exhaust gas temperature is between 852 and 950 °C. In the exhaust gas emission analysis, CO is in the range of 951-1452 ppm, NO between 271 ppm and 303 ppm, CO<inf>2</inf> between 6.5% and 9.5%, and O<inf>2</inf> between 5.1% and 12.8%. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Thermal and swirl flow topologies in a twisted square duct with a multi-twisted tape installed(2020-01-01); Eiamsa-Ard, SmithThis paper presents 3D numerical investigation of the turbulent flow and heat transfer characteristics of a twisted square duct installed with multi-twisted tapes. Air was used as the working fluid with flow rates in terms of Reynolds numbers ranging from 3000 to 20,000. The effects of (1) multi-twisted tape width ratios (w/H) of 0.2 to 1.0 and (2) the number of channels (N = 2 and 4) on heat transfer and flow mechanisms were studied at constant twist ratio of y/D = 3.5. The numerical results showed that twisted square duct combined with twisted tape caused swirl flows which effectively promoted fluid mixing and provided heat transfer over those of both a straight smooth square duct and twisted square duct. Increasing w/H led to increases in both heat transfer and the friction factor. At a given multi-twisted tape width ratio (w/H), the heat transfer and friction factor with N = 4 were higher than those with N = 2, while thermal enhancement factor showed the opposite trend. A maximum thermal enhancement factor of 1.93 was obtained at tape width ratio of w/H = 1.0, channel number of N = 2 and Re = 3000. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Investigation of Combustion Characteristics in a Vortexing Fluidized-bed Combustor with a Contraction Chamber(2023-01-01); ; ; Eiamsa-Ard, SmithThis investigation was undertaken to obtain information on the effects of a contraction chamber and secondary air ratio (λ) on combustion temperature distribution, gas emissions of rice husk combustion and flow behaviours in a vortexing fluidized-bed combustor with a contracted chamber (VFBCC).The combustor chamber was modified by reducing the diameter chamber size (contraction) near the top part of the chamber to create a large central recirculation zone. In the experiment, the effects of secondary air ratio (λ) of 0.0, 0.25 and 0.4, and the equivalent ratio, (ϕ) of 0.2, 0.25, 0.3 on combustion characteristics and temperature distribution were examined. The results indicated that the temperature profile inside the combustor between a typical vortexing fluidized-bed combustor (VFBC) and VFBCC was slightly different.The emission of VFBCC was lower than in the original VFBC. At the equivalent ratio of 0.3 and secondary air ratio of 0.4, the average concentrations of O2, CO2, CO and NOx of the flue gases from the original VFBC were 10.5%, 6.7%, 717 ppm and 287 ppm, respectively while those from the modified VFBCC were 9.7%, 6.3%, 357 ppm, and 250 ppm, respectively. In addition, flow visualization results showed the presence of a contracted part led to the recirculation formation in the top chamber. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Thermal Visualization and Performance Analysis in a Channel Installing Transverse Baffles with Square Wings(2022-11-01); The experimental examination of local heat transfer, thermal intensification, friction factors, and thermal performance factors (TPF) in a rectangular channel with square-winged transverse baffles (SW-TB) are presented in this paper. The purpose of this study is to modify the typical transverse baffles (TB) into square-winged transverse baffles (SW-TB) in order to improve the thermal performance and heat transfer rate of the channel. The effects of SW-TBs with various wing attack angles and Reynolds numbers on the heat transfer performance characteristics were examined using a thermochromic liquid crystal sheet. In the experiments, the SW-TBs were attached to the bottom wall of the channel, which had an aspect ratio (W:H) of 3.75:1. The SW-TBs had a width (w) of 150 mm, a square perforated cross-sectional area (a × b) of 8 × 8 mm<sup>2</sup>, and attack angles (θ) of 0° (solid transverse-baffle), 22.5°, 45°, 67.5°, and 90°. The bottom wall of the channel was evenly heated, while the other walls were insulated. The temperature contours on the heated surface were plotted using temperatures obtained through using the thermochromic liquid crystal (TLC) image-processing method. Experimental results revealed that the SW-TBs created multiple impinging jets, apart from the recirculation. At the proper attack angles (θ = 22.5° and 45°), the SW-TBs offered greater heat transfer rates and caused lower friction losses, resulting in higher TPFs than the solid transverse baffles. In the current work, channels where the SW-TBs display a θ = 45° presented the greatest TPF, as high as 1.26. The multiple impinging jets issuing by the SW-TBs suppressed the size of the recirculation flow and allowed better contact between the fluid flow and channel wall. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Evaluation of heat transfer performance of a channel mounted with square-wing perforated V-type baffles(2025-01-01); ; Maruyama, NaokiThe current study examines the aerothermal performance behaviors of a rectangular-channel with square-wing perforated V-type baffles (SW-PVBs). The SW-PVBs were attached to lower channel walls at five attack angles, θ = 0° (solid V-type baffle), 22.5°, 45°, 67.5° and 90°. The heat transfer and pressure drop results of a channel without SW-PVBs were performed to normalize the results of the SW-PVBs and evaluate thermal performance factors (TPFs). It can be observed that as the attack angles decreased, the heat transfer and pressure loss rose. Among the SW-PVBs that were tested, those characterized by θ = 22.5° exhibited the most significant improvement in heat transfer, whereas SW-PVBs with θ = 45° gave the highest thermal performance factors. Additionally, the SW-PVBs with θ = 45° offered the highest TPF, as high as 1.93. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Heat transfer rate of swirling impinging jets issuing from a twisted tetra-lobed nozzle(2020-12-01); Eiamsa-Ard, SmithHeat transfer augmentation by swirling impinging jets delivered through twisted tetra-lobed nozzles (T-LT) is reported. Impinging jets delivered through a circular nozzle (CT: non-swirling jet) and a tetra-lobed nozzle (LT: non-swirling jet) were also tested for comparison. Experimental results showed that Nusselt numbers of impinging jets delivered through all nozzles were increased with Re and decreasing L/Dh. At a given jet Reynolds number (Re) and a jet-to-plate spacing (L/Dh), the impinging jets delivered through the twisted tetra-lobed nozzles and tetra-lobed nozzle yielded superior heat transfer to that delivered by a circular nozzle. For the jets delivered through the twisted tetra-lobed nozzles, the stagnation Nusselt number (Nu) was decreased while the radial heat transfer distribution was improved with decreasing twist ratios of the nozzle. For the investigated range, the jet delivered through the twisted tetra-lobed nozzle with twist ratio of 4.0 yielded a maximal average Nusselt number. Furthermore, the twisted tetra-lobed nozzles (T-LT) with twist ratios of y/Dh = 2.0, 3.0, 4.0 and 5.0 generate higher heat transfer rates than those of the circular nozzle (CT: non-swirling jet) by around 27.7%, 25.0%, 21.6% and 19.3%, respectively. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Heat transfer visualization of swirling impinging jets using nozzle with centrally hollow helical-tape(2020-05-01)