Article
Energy & Fuels
Boonsong Samutpraphut, Smith Eiamsa-ard, Varesa Chuwattanakul, Chinaruk Thianpong, Naoki Maruyama, Masafumi Hirota
Summary: This article explores the use of sawtooth twisted tapes to enhance heat transfer rate by generating swirling flow and interrupted flowing disturbance. The effects of sawtooth angles on heat transfer rate, friction factor, and aerothermal performance index are analyzed. The results show that the sawtooth twisted tape improves heat transfer rate and introduces varying levels of pressure loss based on the sawtooth angles. The recommended sawtooth twisted tape outperforms the typical twisted tape and plain tube in terms of Nusselt number.
Article
Thermodynamics
Mohammad Zaboli, Mehdi Nourbakhsh, Seyed Soheil Mousavi Ajarostaghi
Summary: This study numerically evaluates heat transfer and fluid flow in a corrugate coil tube with different lobe-shaped cross-sections. Spiral twisted tapes with various geometries are used as turbulators in the tube. The results show that a five-lobe cross-section increases the Nusselt number and pressure drop, and increasing the area of the twisted tape also increases these parameters. Additionally, a spiral twisted tape with cleared center improves thermal efficiency in certain cases.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2022)
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
H. Harish, K. Manjunath
Summary: This research compares the flow and heat transfer properties of water with circular protruded twisted-tape inserts to those with traditional twisted tapes. The study found that circular protruded twisted-tape inserts provide higher thermal enhancement and lower friction factor.
CASE STUDIES IN THERMAL ENGINEERING
(2022)
Article
Thermodynamics
Mohammad Abbaszadeh, Mohammad Hossein Montazeri, Mojtaba Mirzaie
Summary: This study proposes a novel implementation of twisted tape in sinusoidal wavy-walled tubes to enhance heat transfer rate without compromising thermal efficiency. The study numerically investigates the effect of different geometrical configurations on heat transfer improvement and performance factor. The results suggest that implementing twisted tape in wavy tubes significantly increases heat transfer rate and performance factor.
INTERNATIONAL JOURNAL OF NUMERICAL METHODS FOR HEAT & FLUID FLOW
(2023)
Article
Nuclear Science & Technology
Tenglong Cong, Bicheng Wang, Hanyang Gu
Summary: This article presents a numerical analysis of sCO2 heat transfer deterioration and the heat transfer enhancement of twisted tape. The results indicate that adding twisted tape can effectively suppress the heat transfer deterioration and the enhancement is more significant with a smaller twist ratio.
NUCLEAR ENGINEERING AND DESIGN
(2022)
Article
Thermodynamics
Chao Luo, KeWei Song
Summary: The novel twisted annulus design in a double-tube heat exchanger shows excellent thermohydraulic performance, significantly enhancing heat transfer efficiency. The results demonstrate the generation of strong secondary flow within the twisted annulus, leading to a significant improvement in heat transfer effectiveness.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2021)
Article
Thermodynamics
Toygun Dagdevir, Veysel Ozceyhan
Summary: The effects of different twisted tapes on heat transfer and flow characteristics in a heat exchanger tube were experimentally investigated to enhance performance. Results showed that twisted tape inserts improved heat transfer performance, with the novel dimpled twisted tape insert providing the best performance. Addition of ethylene glycol did not significantly increase the friction factor, and higher ethylene glycol content led to decreased thermo-hydraulic performance.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2021)
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
Energy & Fuels
Ramin Zarei, Kiyanoosh Razzaghi, Farhad Shahraki
Summary: This experimental study focused on heat transfer enhancement in laminar flow using different blade crossing angles of mixers in a tube. Results revealed that the 90 degrees blade mixer provided higher Nusselt numbers compared to the 120 degrees mixer, with higher pressure drop as a trade-off. Moreover, the heat transfer enhancement was correlated with the Graetz number, showing that heat transfer effects significantly dominated pressure drop effects.
CHEMICAL ENGINEERING AND PROCESSING-PROCESS INTENSIFICATION
(2021)
Article
Energy & Fuels
Rishabh Agarwal, Rajesh Maithani, Sachin Sharma, Anil Kumar, Ajay Kumar
Summary: This study optimized the parameters of twisted tape insert in a heat exchanger tube with SiO2/H2O based nanofluid flow. The goal was to maximize heat transfer while minimizing pressure drop. The optimized parameter values for a specific range of Reynolds number were found to be W-T/D-T of 0.8, L-T/W-T of 1.74, phi of 1.25 vol.%, and Re of 17,000.
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
(2022)
Article
Thermodynamics
Li Shijie, Qian Zuoqin, Wang Qiang
Summary: This numerical investigation explores the heat transfer optimization effect of circular tube heat exchanger with L-shaped twisted tape insert and finds the optimal parameter design. The effects of twist pitch, inner diameter, tape width, and number of tape on thermohydraulic performance were studied. Response surface method was used to analyze the relationship between the Nusselt number and these parameters. The results show that the tube fitted with L-shaped twisted tape insert has a significant increase in Nu and friction factor compared to the smooth tube.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(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
Ayhan Nazmi Ilikan
Summary: Energy efficiency is a key concern in pipe systems, especially when heat transfer plays a significant role. Twisted tape insertion has been used to improve heat transfer in pipes. This numerical study investigated the variations of Nusselt number (Nu) and friction factor (f) with different length ratios (LR) of twisted tapes, Reynolds number values (Re), and flow conditions. The results suggest that an LR of 70% provides the optimal combination of maximum heat transfer and minimum friction, outperforming completely filling the tube with twisted tape.
ENERGY SOURCES PART A-RECOVERY UTILIZATION AND ENVIRONMENTAL EFFECTS
(2023)
Article
Thermodynamics
Sara Taheripour, Mohammad Reza Saffarian, Noushin Azimy, Mehrsa Aghajari
Summary: This study investigates the heat transfer, friction factor, and thermal enhancement factor in a tube with different twisted-tape geometries. The findings show that triangular elements exhibit the most notable increase in Nusselt number compared to other shapes. Triangular elements also have the highest friction factor compared to square elements. The square with protrusions at 0 degrees has the maximum thermal enhancement factor, while the twist without elements has the lowest thermal enhancement factor.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2023)
Article
Thermodynamics
Mahsa Taghavi, Swapnil Sharma, Vemuri Balakotaiah
Summary: This study investigates the natural convection effects in the insulation layers of spherical storage tanks and their impact on the tanks' performance. The permeability and Rayleigh number of the insulation material are considered as key factors. The results show that as the Rayleigh number increases, new convective cells emerge and cause the cold boundary to approach the external hot boundary. In the case of large temperature differences, multiple solutions may coexist.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Jinyang Xu, Fangjun Hong, Chaoyang Zhang
Summary: This study introduces a self-induced jet impingement device for enhancing pool boiling performance in high power electronic cooling. Through visualization and parametric investigations, the effects of this device on pool boiling performance are studied, revealing the promotion of additional liquid supply and vapor exhausting. The flow rate of the liquid jet is found to positively impact boiling performance.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Wenchao Ke, Yuan Liu, Fissha Biruke Teshome, Zhi Zeng
Summary: Underwater wet laser welding (UWLW) is a promising and labor-saving repair technique. A thermal multi-phase flow model was developed to study the heat transfer, fluid dynamics, and phase transitions during UWLW. The results show that UWLW creates a water keyhole, making the welding environment similar to in air laser welding.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Xingrong Lian, Lin Tian, Zengyao Li, Xinpeng Zhao
Summary: This study investigates the heat transfer mechanisms in natural fiber-derived porous structures and finds that thermal radiation has a significant impact on the thermal conductivity in low-density regions, while natural convection rarely occurs. Insulation materials derived from micron-sized natural fibers can achieve minimum thermal conductivity at specific densities. Strategies to lower the thermal conductivity include increasing porosity and incorporating nanoscale pores using nanosize fibers.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Yasir A. Malik, Kilian Koebschall, Stephan Bansmer, Cameron Tropea, Jeanette Hussong, Philippe Villedieu
Summary: Ice crystal icing is a significant hazard in aviation, and accurate modeling of sticking efficiency is essential. In this study, icing wind tunnel experiments were conducted to quantify the volumetric liquid water fraction, sticking efficiency, and maximum thickness of ice layers. Two measurement techniques, calorimetry and capacitive measurements, were used to measure the liquid water content and distribution in the ice layers. The experiments showed that increasing wet bulb temperatures and substrate heat flux significantly increased sticking efficiency and maximum ice layer thickness.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Jinqi Hu, Tongtong Geng, Kun Wang, Yuanhong Fan, Chunhua Min, Hsien Chin Su
Summary: This study experimentally examined the heat dissipation of vibrating fans and demonstrated its inherent mechanism through numerical simulation. The results showed that the flow fields induced by the vibrating blades exhibited pulsating features and formed large-scale and small-scale vortical structures, significantly improving heat dissipation. The study also identified the impacts of different blade structures and developed a trapezoidal-folding blade, which effectively reduced the maximum temperature of the heat source and alleviated high-temperature failure crisis.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Dan-Dan Su, Xiao-Bin Li, Hong-Na Zhang, Feng-Chen Li
Summary: The boiling heat transfer of low-boiling-point working fluid is a common heat dissipation technology in electronic equipment cooling. This study analyzed the interfacial boiling behavior of R134a under different conditions and found that factors such as the initial thickness of the liquid film, solid-liquid interaction force, and initial temperature significantly affect the boiling mode and thermal resistance.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Jinyi Wu, Dongke Sun, Wei Chen, Zhenhua Chai
Summary: A unified lattice Boltzmann-phase field scheme is proposed to simulate dendrite growth of binary alloys in the presence of melt convection. The effects of various factors on the growth are investigated numerically, and the model is validated through comparisons and examinations.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Shaokun Ge, Ya Ni, Fubao Zhou, Wangzhaonan Shen, Jia Li, Fengqi Guo, Bobo Shi
Summary: This study investigated the temperature distribution of main cables in a suspension bridge during fire scenarios and proposed a prediction model for the maximum temperature of cables in different lane fires. The results showed that vehicle fires in the emergency lane posed a greater thermal threat to the cables.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Shuang-Ying Wu, Shi-Yao Zhou, Lan Xiao, Jia Luo
Summary: This paper investigates the two-phase flow and heat transfer characteristics of low-velocity jet impacting on a cylindrical surface. The study reveals that the heat transfer regimes are non-phase transition and nucleate boiling with the increase of heat transfer rate. The effects of jet impact height and outlet velocity on local surface temperatures are pronounced at the non-phase transition stage. The growth rates of heat transfer rate and liquid loss rate increase significantly from the non-phase transition to nucleate boiling stage.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Emad Hasani Malekshah, Wlodzimierz Wlodzimierz, Miros law Majkut
Summary: Cavitation has significant practical importance and can be controlled by air injection. This study investigates the natural to ventilated cavitation process around a hydrofoil through numerical and experimental methods. The results show that the location and rate of air injection have a meaningful impact on the characteristics of cavitation.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Feriel Yahiat, Pascale Bouvier, Antoine Beauvillier, Serge Russeil, Christophe Andre, Daniel Bougeard
Summary: This study explores the enhancement of mixing performance in laminar flow equipment by investigating the generation of chaotic advection using wall deformations in annular geometries. The findings demonstrate that the combined geometry can achieve perfect mixing at various Reynolds numbers.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Hui He, Ning Lyu, Caihua Liang, Feng Wang, Xiaosong Zhang
Summary: This study investigates the condensation, frosting, and defrosting processes on superhydrophobic surfaces with millimeter-scale structures. The results reveal that the structures can influence the growth and removal of frost crystals, with the bottom grooves creating a frost-free zone and conical edges promoting higher frost crystal heights. Two effective methods for defrosting are observed: hand-lifting the groove and airfoil retraction contraction on protruding structures. This research provides valuable insights into frost formation and defrosting on millimeter-structured superhydrophobic surfaces, with potential applications in anti-frost engineering.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Thiwanka Arepolage, Christophe Verdy, Thibaut Sylvestre, Aymeric Leray, Sebastien Euphrasie
Summary: This study developed two thermal concentrators, one with a 2D design of uniform thickness and another with a 3D design, using the coordinate transformation technique and metamaterials. By structuring the thermal conductor, the desired local density-heat capacity product and anisotropic thermal conductivities were achieved. The homogenized thermal conductivities were obtained from finite element simulations and cylindrical symmetry consideration. A 3D concentrator was fabricated using 3D metal printing and characterized using a thermal camera. Compared to devices that solely consider anisotropic conductivities, the time evolution characteristics of the metadevice designed with coordinate transformation were closer to those of an ideal concentrator.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Liangyuan Cheng, Qingyang Wang, Jinliang Xu
Summary: In this study, we investigated the supercritical heat transfer of CO2 in a horizontal tube with a diameter of 10.0 mm, covering a wide range of pressures, mass fluxes, and heat fluxes. The study revealed a non-monotonic increase in wall temperatures along the flow direction and observed both positive and negative wall temperature differences between the bottom and top tube. The findings were explained by the thermal conduction in the solid wall interacting with the stratified-wavy flow in the tube.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)