Article
Thermodynamics
Yuxiang Hong, Lei Zhao, Yongchun Huang, Qing Li, Jiajie Jiang, Juan Du
Summary: Waste heat recovery technology is crucial for energy conservation and emission reduction, and the efficiency of heat exchangers plays a decisive role in waste heat recovery. In this study, a synergistic thermal enhancement technology was devised using a spiral corrugated tube (SCT) and multiple twisted tapes (TTs) to improve the heat transfer potential of conventional heat exchangers. Numerical investigations showed that fitting multiple TTs into the SCT homogenized flow fields and temperature distributions, and increased heat transfer efficiency. Perforations on the surface of the TTs reduced friction factor without compromising heat transfer efficiency. By simple perforations, the maximum overall thermal performance evaluation index could be enhanced by around 7.9%.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2023)
Article
Thermodynamics
Mohammad Rejaul Haque, Tajin Jahan Hridi, M. Merajul Haque
Summary: This study investigates the effect of forced convection heat transfer for various innovative shaped pin fin heatsink designs. The results show that the use of twisted and grooved shaped pin fins can improve the heat transfer rate and hydrothermal performance factor. Specifically, the grooved circular perforated pin fin has shown a 9% increase in HTPF under specific conditions.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2022)
Article
Thermodynamics
Kim Leong Liaw, Jundika C. Kurnia, Agus P. Sasmito
Summary: This study investigates the convective heat transfer performance of Newtonian fluid in a helical twisted multilobe tube using computational fluid dynamics (CFD) simulations. The results show that the combination of number of lobes and tube twisting has a significant effect on the heat transfer coefficient, while increasing the number of lobes alone has a minimal impact. The helical coiled tube outperforms the straight tube within a certain range of Reynolds numbers, while twisting is recommended primarily for straight tubes.
CASE STUDIES IN THERMAL ENGINEERING
(2022)
Article
Thermodynamics
M. Pimsarn, P. Samruaisin, C. Thianpong, K. Ruengpayungsak, P. Eiamsa-ard, S. Chamoli, S. Eiamsa-ard
Summary: This study optimized the aerothermal performance of a tube with inclined circular-rings (ICRs) and twisted-tapes (TTs), and found that the heat transfer and friction factor increase with the number of twisted tapes and decrease with twist ratio. The heat transfer of ICRs together with TTs is significantly higher than in a plain tube and other configurations, achieving a maximal eta of 1.66.
CASE STUDIES IN THERMAL ENGINEERING
(2022)
Article
Engineering, Chemical
Chuanshuai Dong, Lin Lu, Tao Wen, Shaojie Zhang
Summary: This study investigated the thermal performance of heat transfer devices using self-rotating twisted tapes (SRTTs) and Al2O3 nanoparticles. Experimental results showed significant improvement in heat transfer rate with SRTTs, and superior thermal performance with the combined application of Al2O3 nanoparticles and SRTTs. New heat transfer and friction factor correlations were developed considering the combined effect of Al2O3 nanoparticle and SRTTs.
CHINESE JOURNAL OF CHEMICAL ENGINEERING
(2021)
Article
Thermodynamics
Aziz Hakan Altun, Haluk Nacak, Eyub Canli
Summary: The trapezoidal and twisted trapezoidal tape elements used for heat transfer enhancement in tubes were experimentally investigated, analyzing their effects on heat transfer, pressure drop, and overall performance factor. The experimental results showed that the twisted trapezoidal tape elements had excellent heat transfer performance and overall performance factor.
APPLIED THERMAL ENGINEERING
(2022)
Article
Thermodynamics
Abdullah Masoud Ali, Aldo Rona, Matteo Angelino
Summary: This study investigates the thermo-hydraulic performance of water-cooled silicon microchannel heat sinks with tape inserts. The numerical simulations show that the tape inserts improve the thermal performance of the heat sinks. Among the different configurations tested, heat sinks with four L/4 alternating pitch consecutive helical tape segments exhibit the lowest average temperature of the bottom wall, with a temperature drop of 16.13 K compared to the baseline configuration without tape.
INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW
(2022)
Article
Thermodynamics
Hong-Jin Joo, Hee-Youl Kwak, Minsuk Kong
Summary: The present study experimentally investigates the effect of twisted tape inserts on the thermal performance of an eccentric inlet and outlet heat pipe evacuated-tube solar thermal collector (HP-ESTC). The results show that the addition of twisted tape inserts enhances heat transfer performance by eliminating stagnation flow, reducing flow skewness, and generating rotating flow. A comprehensive performance analysis considering both heat transfer and pressure drop characteristics confirms that using twisted tape inserts can improve overall performance by approximately 7.7%. To assess its applicability for commercial HP-ESTCs, an HP-ESTC containing twisted tape inserts was manufactured and tested outdoors.
Article
Energy & Fuels
Hakan Bucak, Fuat Yilmaz
Summary: The study examined the thermal-hydraulic performance of twisted tapes with teardrop-shaped dimple-protrusion patterned walls, finding that certain designs had higher Nusselt number and thermal performance factor within specific Reynolds number ranges.
CHEMICAL ENGINEERING AND PROCESSING-PROCESS INTENSIFICATION
(2021)
Article
Thermodynamics
Changgui Xie, Ibrahim B. Mansir, Ibrahim Mahariq, Pradeep Kumar Singh, Akbar Arsalanloo, Rehman Muhammad Shahzad, Fahd Jarad
Summary: This study experimentally investigates the influence of using twisted tape turbulator and changing the pitch on fluid flow and heat transfer inside a helical tube. The results show that the application of twisted tape can significantly enhance the heat transfer rate, especially with smaller twist pitch.
CASE STUDIES IN THERMAL ENGINEERING
(2022)
Article
Energy & Fuels
Wang Xifeng, Zhang Xiaoluan, Ibrahim Mahariq, Mohamed Salem, Mohammad Ghalandari, Farhad Ghadak, Mostafa Abedini
Summary: This paper presents the optimization of a two-tube helical heat exchanger with fins. The study investigates the effects of different geometric shapes of fins on the overall heat transfer coefficient and pressure loss. The results show a significant improvement in heat transfer efficiency and reduction in pressure loss with the optimized fin design.
FRONTIERS IN ENERGY RESEARCH
(2022)
Article
Thermodynamics
Anurag Maheswari, Yogesh K. Prajapati
Summary: In the present study, a three-dimensional numerical simulation was conducted to investigate the thermohydraulic performance of a novel design of double-layer microchannel heat sinks. The modified heat sink with an intermediate rectangular fin and different hole shapes significantly enhanced the heat transfer rate by approximately 45-60% compared to the conventional design. However, higher pressure drops were observed due to flow restrictions. Among all the cases considered, heat sinks with circular and triangular holes showed superior thermal performance with a marginal difference of approximately 2-5%. The improved heat transfer rate in the modified heat sink was attributed to better fluid mixing and thinner boundary layers facilitated by the fins with holes. Optimization analysis identified a heat sink with a hole radius of 0.286 mm and 15 holes as the superior configuration, achieving a maximum heat transfer rate approximately 51-64% higher than the conventional design.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2023)
Article
Thermodynamics
Toygun Dagdevir, Mahmut Uyanik, Veysel Ozceyhan
Summary: Experimental investigation on heat transfer enhancement using various twisted tape inserted tube configurations under turbulent flow conditions. Results show that DTTEs have better heat transfer performance compared to PTTEs, while PTTEs have less friction loss.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2021)
Article
Thermodynamics
Xuanxuan Huang, Liang Wang, Xiao Li
Summary: This study improves the heat collection performance of solar air heaters and reduces internal pressure by introducing a collector with perforated baffle. The simulation results show that the perforated baffle collectors have lower pressure loss, higher collection efficiency, lower heat dissipation coefficient, and higher heat transfer coefficient compared to non-perforated baffle collectors. The coupling between heat collection efficiency and pressure loss is optimized when the hole height is 30 mm, the hole diameter is 80 mm, and the hole-opened rate is 0.24. The perforated-folded baffle collector provides a theoretical basis for improving the solar thermal utilization rate.
NUMERICAL HEAT TRANSFER PART A-APPLICATIONS
(2023)
Article
Thermodynamics
Kim Leong Liaw, Jundika C. Kurnia, Agus P. Sasmito
Summary: This study investigated the effect of inserting twisted tape into a helical tube on turbulent heat transfer, finding that the insertion of twisted tape increases the intensity of secondary flow in the radial direction, resulting in higher heat transfer performance. The results also showed that for all cases, higher inlet Reynolds numbers lead to a proportional increase in heat transfer, while the friction coefficient decreases with decreasing decrement amounts.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Thermodynamics
C. Thianpong, K. Wongcharee, H. Safikhani, S. Chokphoemphun, A. Saysroy, S. Skullong, S. Eiamsa-ard
Summary: This study utilized a hybrid technique involving TiO2/water nanofluid and loose-fit delta-wing twisted tape to enhance heat transfer efficiency. Experimental results showed that the combined enhancement technique significantly improved heat transfer rates, mainly due to the swirling flow effect and higher thermal conductivity. Furthermore, reducing the loose-fit ratio and increasing the nanofluid concentration can also enhance heat transfer rates and thermohydraulic performance.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2022)
Article
Thermodynamics
S. Eiamsa-ard, A. Suksangpanomrung, P. Promthaisong
Summary: This study presents a numerical analysis of heat transfer mechanism and flow topology of channels with V-shaped baffles (VB) and semi-circular hinged V-shaped baffles (SH-VB). The results show that SH-VB provides higher heat transfer enhancement and lower pressure losses compared to VB. The optimum parameters for maximum thermal enhancement factor (TEF) are BR = 0.10, PR = 0.5 and beta = 10 degrees.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2022)
Article
Thermodynamics
Nuthvipa Jayranaiwachira, Pongjet Promvonge, Chinaruk Thianpong, Sompol Skullong
Summary: This article presents an experimental study on entropy generation analysis and thermohydraulic performance of a uniform heat-flux tube equipped with louvered corner-curved baffle tape (LCBT). The impacts of various parameters on the thermal enhancement factor, Nusselt number, friction factor, and total entropy generation were examined. The results indicate that the LCBT with smaller pitch ratios and angles performs better in terms of thermal performance, especially at higher Reynolds numbers.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Thermodynamics
Smith Eiamsa-Ard, Arnut Phila, Monsak Pimsarn, Naoki Maruyama, Masafumi Hirota
Summary: The aim of this study is to investigate the effect of wing position on heat transfer rate and pressure drop characteristics in a channel with square-wing perforated transverse baffles. Two types of baffles, solid and square-wing, were tested at various Reynolds numbers. The results showed that square-wing baffles have lower pressure losses and higher thermal performance compared to solid baffles.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2023)
Article
Thermodynamics
Pongjet Promvonge, Arnut Phila, Varesa Chuwattanakul, Suriya Chokphoemphun, Smith Eiamsa-ard, Naoki Maruyama, Masafumi Hirota
Summary: In this study, the use of arc-shaped twisted-baffles (T-ABs) in a rectangular air channel was experimentally investigated to improve the thermal performance factor (TPF). The effects of pitch ratio (p/w), arc-shape angle (alpha), and Reynolds number (Re) were explored. The results showed that the channel with arc-shaped twisted-baffles achieved higher Nusselt numbers compared to a smooth channel, likely due to the presence of multiple-impinging jets near the surface. Baffles with larger attack angles exhibited superior heat transfer enhancements. The optimal condition was found at alpha = 90o, p/w = 4.0, and Re = 4000, resulting in significant improvements in heat transfer rate, friction factor, and TPF.
CASE STUDIES IN THERMAL ENGINEERING
(2023)
Article
Thermodynamics
V. Chuwattanakul, K. Wongcharee, P. Ketain, S. Chamoli, C. Thianpong, S. Eiamsa-ard
Summary: An experimental investigation on the aerothermal performance of a heat exchanger tube equipped with newly designed broken V-ribbed twisted tapes (B-VRT) was conducted. The results showed that the B-VRT provided enhanced heat transfer due to increased mixing caused by longitudinal vortices from the ribs and swirling flow from the twisted tapes. The B-VRT with forward facing ribs at an attack angle alpha of 45 degrees exhibited the best performance.
CASE STUDIES IN THERMAL ENGINEERING
(2023)
Article
Energy & Fuels
Smith Eiamsa-ard, Arnut Phila, Khwanchit Wongcharee, Monsak Pimsarn, Naoki Maruyama, Masafumi Hirota
Summary: The influences of perforated-baffles on local Nusselt number and thermo-hydraulic behaviors were comprehensively studied using thermochromic liquid crystal sheet. The study found that perforated-baffle with square wings offered better results compared to regular perforated-baffles, and caused less pressure loss.
Article
Energy & Fuels
Prachya Samruaisin, Rangsan Maza, Chinaruk Thianpong, Varesa Chuwattanakul, Naoki Maruyama, Masafumi Hirota, Smith Eiamsa-ard
Summary: The influences of V-shaped delta-wing baffles on the thermohydraulic performance in a round tube were experimentally tested. The V-shaped delta-wing baffles with a set number of wings (N=4, 6, and 8) and various pitch ratios (P/D=2.0, 2.5, and 3.0) were studied. The results showed that the V-shaped delta-wing baffles can significantly enhance the Nusselt number and improve the heat transfer rate.
Article
Thermodynamics
S. Sirikasemsuk, N. Naphon, S. Eiamsa-ard, P. Naphon
Summary: The operating temperature of the battery has a significant impact on the performance, reliability, and safety of electric vehicles. A 3D Eulerian model is used to study the battery's thermal behavior under different coolant flow directions. The results show that the coolant flow direction and thermophysical properties have a significant effect on the maximum operating temperature and temperature gradient of the battery. The proposed battery nanofluid cooling pack can optimize the thermal management system of electric vehicle packs.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Thermodynamics
Pongjet Promvonge, Smith Eiamsa-ard, Sompol Skullong, Naoki Maruyama, Masafumi Hirota
Summary: An experiment was conducted to investigate the effectiveness of inserting a louver-punched trapezoidal-winglet into a heat-fluxed tube to create a longitudinal vortex generator. The study aimed to optimize thermal performance and reduce heat exchanger sizes. The experimental results showed significant improvements in friction factor and Nusselt number compared to a plain tube.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Thermodynamics
Smith Eiamsa-ard, Naoki Maruyama, Masafumi Hirota, Sompol Skullong, Pitak Promthaisong
Summary: This paper investigates the fluid flow and heat transfer mechanisms in ribbed twisted-oval tubes. Simulations were conducted to find the optimal conditions for uniform heat-flux wall condition in turbulent flow. The results show that the ribbed twisted-oval tubes generate stronger swirl flow and have higher turbulent kinetic energy compared to conventional twisted-oval tubes. With increasing rib height ratios, spiral depth ratios, and number of ribs, the turbulent kinetic energy increases significantly while it decreases with larger twist pitch ratios. The optimal parameters for maximal thermal performance factor (TPF) of 1.32 were found to be a twist pitch ratio of 3.5, a spiral depth ratio of 0.1, a rib height ratio of 0.075, a number of ribs of 4, and a Reynolds number of 5000.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2023)
Article
Thermodynamics
K. Nanan, S. Eiamsa-ard, S. Chokphoemphun, Manoj Kumar, M. Pimsarn, V. Chuwattanakul
Summary: The aim of this study was to investigate the shrimp drying process in a fluidized-bed dryer in order to develop a more efficient method compared to traditional sun drying. The influence of shrimp size, bed height, and air temperature on the drying rate was studied, with the moisture content of boiled shrimp decreasing at higher drying temperatures. Reducing bed height and shrimp size both increased shrimp moisture removal. The highest dried shrimp production rate was achieved at a bed height of 1.0 and drying temperature of 80 degrees C.
CASE STUDIES IN THERMAL ENGINEERING
(2023)
Article
Thermodynamics
Arnut Phila, Warin Keaitnukul, Smith Eiamsa-ard, Paisarn Naphon, Naoki Maruyama, Masafumi Hirota, Varesa Chuwattanakul
Summary: The proper designs of modified heat transfer surfaces or turbulence enhancement inserts are crucial for improving the efficiency of thermal systems. The use of transverse baffles with rectangular notches can effectively enhance heat transfer while minimizing pressure loss. The smaller the ratio of notch height to baffle height, the higher the heat transfer enhancement, friction factor, and aerothermal performance.
CASE STUDIES IN THERMAL ENGINEERING
(2023)
Article
Engineering, Aerospace
P. Eiamsa-ard, K. Wongcharee, K. Kunnarak, M. Kumar, S. Eiamsa-ard, M. Pimsarn
Summary: Thermal visualization was performed to study and compare the heat transfer behavior of different types of jets. The results showed that the swirling impinging jet with a triple spiral-corrugated nozzle and twisted tape inserts had stronger recirculation, leading to reduced heat transfer between the stagnation region and surroundings.
THERMOPHYSICS AND AEROMECHANICS
(2022)
Article
Engineering, Aerospace
S. Eiamsa-ard, V Chuwattanakul, H. Safikhani, P. Promthaisong
Summary: In this paper, multi-objective optimization of geometric parameters of spirally-cross-corrugated (SCC) tubes is carried out using numerical methods, genetic algorithms, and artificial neural networks. The analysis reveals several important optimal design principles for heat transfer in such tubes.
THERMOPHYSICS AND AEROMECHANICS
(2022)