Article
Engineering, Multidisciplinary
Hossam A. Nabwey, A. M. Rashad, Waqar A. Khan, Sumayyah Alshber
Summary: This study investigates the unsteady MHD free convection flow and heat transfer in an inclined U-shaped cavity filled with Cu-water nanofluid. The effects of various parameters, such as heat source length, Hartmann number, nanoparticle volume fraction, heat source location, and aspect ratio, on the mean heat transfer rate are examined. The results show that the mean heat transfer rate decreases with heat source length and Hartmann number, but increases with heat source location and nanoparticle volume fraction. Furthermore, the mean heat transfer rate increases with aspect ratio.
ALEXANDRIA ENGINEERING JOURNAL
(2022)
Article
Engineering, Multidisciplinary
Hossam A. Nabwey, A. M. Rashad, P. Bala Anki Reddy, Shaik Jakeer, M. A. Mansour, T. Salah
Summary: The introduction of hybrid nanofluids has significant applications in various engineering and industrial fields such as low-pressure drop, wider absorption range, generator cooling, good thermal conductivity, nuclear system cooling, and heat exchangers. This study focuses on the unsteady MHD free convection flow of hybrid nanofluid in an inclined wavy permeable enclosure with a square obstacle, considering the effects of radiation and heat generation/absorption. The results show that parameters such as porosity, nanoparticle volume fraction, and Hartmann number have an impact on the average Nusselt number and distribution of isothermal lines.
ALEXANDRIA ENGINEERING JOURNAL
(2023)
Article
Engineering, Multidisciplinary
Nur Syahirah Wahid, Norihan Md Arifin, Najiyah Safwa Khashi'ie, Ioan Pop
Summary: Hybrid nanofluids have shown superior heat transfer performance in various applications, but further research is needed to explore their potential in a wider range of applications. This study analyzes the flow of a radiative magnetohydrodynamic (MHD) mixed convective alumina-copper/water hybrid nanofluid past an inclined shrinking plate. By applying similarity transformations, the flow model's partial differential equations are converted to ordinary differential equations (ODEs). The numerical solution is obtained using the fourth-order accuracy code (bvp4c) for the boundary value problem. The findings suggest that optimizing copper concentration, thermal radiation, and MHD effect can significantly enhance the heat transfer rate and prevent flow separation.
ALEXANDRIA ENGINEERING JOURNAL
(2023)
Article
Energy & Fuels
Khalid Almutairi
Summary: In this study, the cooling of integrated circuits (ICs) was achieved by using natural convection of water/Nano-Encapsulated Phase Change Material (NEPCM), which significantly improved the heat transfer process. The effects of NEPCM volume fraction, Rayleigh number, and inclined angle on the heat transfer parameters were investigated.
JOURNAL OF ENERGY STORAGE
(2022)
Article
Physics, Multidisciplinary
M. Rajarathinam, A. J. Chamkha
Summary: This paper investigates the natural convection of CNT-water-based nanofluid in a square cavity with the presence of a magnetic field and reports the effect of partial open on heat transfer rate. The results show that the impact of partial open on heat transfer rate is insignificant and independent of the position of the opening.
EUROPEAN PHYSICAL JOURNAL PLUS
(2021)
Article
Multidisciplinary Sciences
Usman, Abid Ali Memon, Metib Alghamdi, Taseer Muhammad
Summary: The article investigates heat transfer characteristics of a water alumina nanofluid through a three-dimensional annular. The study found that the average Nusselt number at the middle of the annular increases initially with volume fraction before decreasing, while the average percentage change in temperature relative to the inner cylinder's hot temperature decreases with an increase in volume fraction.
SCIENTIFIC REPORTS
(2022)
Article
Multidisciplinary Sciences
Dolat Khan, Kanayo Kenneth Asogwa, Nevzat Akkurt, Poom Kumam, Wiboonsak Watthayu, Kanokwan Sitthithakerngkiet
Summary: This research explores the electroosmotic flow of Casson-type nanofluid with Sodium Alginate nanoparticles through a vertically tilted microchannel, considering the influence of a transverse magnetic field. The study investigates heat and mass transmission and finds that an increase in the volume fractional of nanoparticles enhances heat transfer rate, skin friction, and Sherwood number, while an increase in the angle of inclination improves fluid velocity.
SCIENTIFIC REPORTS
(2022)
Article
Engineering, Chemical
Rasool Alizadeh, Mehrdad Mesgarpour, Abolhasan Ameri, Javad Mohebbi Najm Abad, Somchai Wongwises
Summary: The article introduces an advanced numerical method that combines Artificial Intelligence and traditional computational methods to expand the application scope of numerical modeling, particularly suitable for complex processes such as natural convection and oscillating heat transfer. Through numerical modeling, the study explores the effects of variable boundary conditions on heat transfer, finding that the amplitude of oscillation significantly affects heat transfer rates.
JOURNAL OF THE TAIWAN INSTITUTE OF CHEMICAL ENGINEERS
(2021)
Article
Multidisciplinary Sciences
Muqdad Al-Maliki, Khaled Al-Farhany, Ioannis E. Sarris
Summary: This paper experimentally investigates the natural convective heat transfer in a rectangular cavity filled with (50% CuO-50% Al2O3)/water hybrid nanofluids connected to a phase change material (PCM). The results show that increasing the concentration of hybrid nanomaterial improves the heat transfer rate by free convection, and the PCM can reduce the temperature of the hot side. Furthermore, the inclusion of hybrid nanofluids enhances the efficiency of heat storage of the PCM.
Article
Engineering, Chemical
Yacine Khetib, Ahmad Aziz Alahmadi, Ali Alzaed, Hamidreza Azimy, Mohsen Sharifpur, Goshtasp Cheraghian
Summary: This paper simulated the free convective heat transfer of nanofluids in a square cavity using numerical methods. The effects of different fin configurations, cavity angles, and magnetic field conditions on heat transfer performance and entropy generation were analyzed. The results showed that tilting or warping the fins improved heat transfer rates, and increasing the Hartmann number reduced both Nusselt number and entropy generation.
Article
Thermodynamics
Shafqat Hussain, Muhammad Jamal, B. Pekmen Geridonmez
Summary: This study investigates the impact of fins and inclined magnetic field on nanofluid heat transfer in lid-driven cavities through numerical simulations. The presence of fins significantly affects fluid flow and heat transfer, with differences observed between adiabatic and isothermal fins.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2021)
Article
Thermodynamics
Khaled Al-Farhany, Kadhim K. Al-Chlaihawi, Mohamed F. Al-dawody, Nirmalendu Biswas, Ali J. Chamkha
Summary: This study numerically investigates the magnetohydrodynamic conjugate heat transfer characteristics of a ferrofluid-filled porous inclined enclosure, with a focus on the influence of parameters such as fins length, gap between fins, modified Rayleigh number, Darcy number, and Hartmann number on the average Nusselt number. The results suggest that the fins length and gap between fins play a significant role in heat transfer enhancement, while the modified Rayleigh number, Darcy number, and Hartmann number also have notable effects.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2021)
Article
Engineering, Multidisciplinary
Tao Hai, Sameer Alsharif, Masood Ashraf Ali, Pradeep Kumar Singh, As'ad Alizadeh
Summary: In this article, the convection of natural alumina/water nanofluid in a rhombus-shaped enclosure was simulated, and the effects of blade and fin parameters on the average Nusselt number, entropy production, and Bejan number were studied. The results showed significant variations of these parameters within certain ranges.
ENGINEERING ANALYSIS WITH BOUNDARY ELEMENTS
(2023)
Article
Engineering, Multidisciplinary
M. A. Mansour, Rama Subba Reddy Gorla, Sadia Siddiqa, A. M. Rashad, T. Salah
Summary: This article presents a numerical investigation of the unsteady magnetohydrodynamics (MHD) natural convection flow in an inclined square cavity filled with nanofluid. The impact of a heated circular obstacle with heat generation/absorption is examined. The study shows that MHD has a dominant effect on the streamlines, isotherms, and average Nusselt number compared to other physical parameters.
INTERNATIONAL JOURNAL OF NONLINEAR SCIENCES AND NUMERICAL SIMULATION
(2023)
Article
Thermodynamics
Nepal Chandra Roy, Sherajum Monira
Summary: The purpose of this study is to investigate the natural convection characteristics of a reacting hybrid nanofluid in an open porous cavity bounded by vertical wavy walls subject to an inclined magnetic field. The resulting equations are solved using finite difference method and numerical results for the streamlines, isotherms and isoconcentration are obtained. The findings reveal the flow patterns and distribution of temperature and concentration in the open space.
INTERNATIONAL JOURNAL OF NUMERICAL METHODS FOR HEAT & FLUID FLOW
(2023)
Article
Engineering, Multidisciplinary
Raoudha Chaabane, Lioua Kolsi, Abdelmajid Jemni, Annunziata D'Orazio
Summary: This study numerically investigates the two-dimensional natural convection in a square enclosure with an isothermal diamond elliptic array. The effects of horizontally and vertically heated arrays on the flow regime are examined. The study demonstrates that the transition from unsteady state to steady state depends on the variation in the ratio of the elliptical cylinder.
INTERNATIONAL JOURNAL OF NONLINEAR SCIENCES AND NUMERICAL SIMULATION
(2023)
Article
Thermodynamics
Emad Hasani Malekshah, Ahmed Kadhim Hussein, Lioua Kolsi
Summary: The purpose of this study is to address the cooling issue of electronic packages by simulating the convective heat transfer of nanofluid flow over dissipating fins using a numerical approach and evaluating the properties of nanofluid based on experimental measurements.
INTERNATIONAL JOURNAL OF NUMERICAL METHODS FOR HEAT & FLUID FLOW
(2023)
Article
Green & Sustainable Science & Technology
Ceylin Sirin, Fatih Selimefendigil, Hakan Fehmi Oztop
Summary: In this study, thermal energy storage unit-integrated photovoltaic thermal (PVT) air collectors with and without nanoparticles were designed, fabricated, and tested. The integration of aluminum oxide nanoparticles into the thermal storage unit improved the performance of the PVT collector, reducing drying time by approximately 15-22%. The use of nanoparticles in the thermal energy storage unit also improved the overall energy and exergy efficiencies of the PVT air collectors, with an increase of 6.91-6.97% and 9.20-9.47%, respectively. The combination of increasing the flow rate and integrating nanoparticles into the storage unit further improved the overall exergetic efficiency of the PVT air collector by 28.58%.
Article
Chemistry, Multidisciplinary
Lioua Kolsi, Fatih Selimefendigil, Hatem Gasmi, Badr M. Alshammari
Summary: In this study, the application of double rotating active cylinders and slot nanojet impingement for the cooling system of a conductive panel is considered. The effects of cylinder rotational speeds, size, and distance between them on the cooling performance are evaluated, revealing that the rotational effects and size of the cylinders significantly impact the thermal performance. Furthermore, subcooling and nanofluid utilization are found to contribute positively to the cooling performance. The estimation of maximum and average panel temperatures using an artificial neural network is also discussed.
Article
Chemistry, Physical
Sofiene Mellouli, Fatma Bouzgarrou, Talal Alqahtani, Salem Algarni, Kaouther Ghachem, Lioua Kolsi
Summary: This study proposes a new configuration of metal hydride (MH) - phase change material (PCM) composite disks, which improves the thermal performance and enhances the release rate and reaction rate of hydrogen by 37.68%. The geometrical parameters of the MH truncated cone and the heat transfer model are optimized to achieve this enhancement.
Article
Green & Sustainable Science & Technology
Fatih Selimefendigil, Damla Okulu, Hakan F. Öztop
Summary: Two different cooling systems were developed for the thermal management of a photovoltaic module. The PV/TEG and PV/TEG-mini-channel cooling systems used water and Al2O3 nanofluids in the cooling channel. Higher-loading nanoparticles in the base fluid achieved effective cooling, and the nanofluid showed non-Newtonian behavior. The PV/TEG-cooling channel with the lowest fluid inlet temperature and the highest particle loading resulted in significantly increased PV efficiency and TEG output power compared to PV/TEG and conventional PV systems without cooling.
Article
Mathematics
Muhammad Ashraf, Anwar Khan, Amir Abbas, Abid Hussanan, Kaouther Ghachem, Chemseddine Maatki, Lioua Kolsi
Summary: The study investigates the physical effects of thermal radiation on heat and mass transfer of a nanofluid around a sphere. Using non-dimensional variables, the governing partial differential equations are transformed into a dimensionless form. Numerical simulations are conducted using the finite difference method to analyze the impact of different parameters on velocity, temperature, and concentration. The results demonstrate that the radiation parameter, thermophoresis parameter, and Brownian motion parameter intensify the profiles of these variables at different positions on the sphere.
Article
Mathematics
Lioua Kolsi, Ahmed Kadhim Hussein, Walid Hassen, Lotfi Ben Said, Badreddine Ayadi, Wajdi Rajhi, Taher Labidi, Ali Shawabkeh, Katta Ramesh
Summary: A numerical investigation was conducted on a PCM energy storage tank using CNT-water nanofluid, under actual climatic conditions of Ha'il region, Saudi Arabia. It was found that using CNT-nanofluid led to a reduction in charging time and improved performance. An increase in flow rate accelerated the melting process. The use of baffles had no beneficial effects on the melting process.
Article
Mathematics
Sardar Bilal, Imtiaz Ali Shah, Kaouther Ghachem, Abdelkarim Aydi, Lioua Kolsi
Summary: Fluids with high hydrothermal characteristics, known as nanofluids, have been developed by adding dispersed nanoparticles to base fluids. Among these, multi-walled carbon nanotubes (MWCNTs) are considered the best option due to their significant enhancement of thermophysical properties and solution stability. This study analyzes the heat transfer characteristics of MWCNT-water nanofluid in a star-shaped cavity with a hot rectangular baffle. Numerical simulations are conducted using COMSOL and PARADISO software, and the effects of governing parameters on velocity and temperature fields are presented through streamlines and isotherms.
Article
Multidisciplinary Sciences
Amir Abbas, Muhammad Ashraf, Hafeez Ahmad, Kaouther Ghachem, Zia Ullah, Abid Hussanan, Taher Labidi, Lioua Kolsi
Summary: The current work focuses on studying the effects of radiation, Darcy-Forchheimer relation, and reduced gravity on magnetohydrodynamic flow across a solid sphere in porous material. The study establishes coupled and nonlinear partial differential equations to model the configuration and converts them to dimensionless form using appropriate scaling variables. A numerical algorithm based on the finite element approach is developed to solve the problem, and the proposed model is validated by comparing with published results. The study aims to demonstrate the impact of Darcy-Forchheimer law and reduced gravity on natural convective heat transfer, and the results show that flow intensity decreases with certain parameters while temperature increases with others.
Article
Physics, Applied
Samah Maatoug, Kamel Al-Khaled, Ali Raza, Taher Labidi, Lioua Kolsi, Wathek Chammam, Muqrin Almuqrin, Sami Ullah Khan
Summary: The aim of this research is to investigate the thermal enhancement of hybrid nanofluids. By incorporating titanium dioxide and silver nanoparticles, the thermal properties of the nanofluids are improved. The Casson fluid model is used to describe the base fluids, and fractional simulations are performed using the Caputo-Fabrizio time-fractional derivatives and Laplace technique. The results show that the Grashof number, Nusselt number, and wall shear force increase with the fractional parameters.
INTERNATIONAL JOURNAL OF MODERN PHYSICS B
(2023)
Article
Physics, Applied
Mohammed A. Almeshaal, Murugesan Palaniappan, Lioua Kolsi
Summary: This study aims to report the significance of induced magnetic force for non-Newtonian nanofluid containing microorganisms. The thixotropic non-Newtonian fluid model is used to classify the distinct rheological impact. The bioconvective thermal model is presented in view of variable thermal conductivity. The problem is further entertained with thermal radiation impact and activation energy.
INTERNATIONAL JOURNAL OF MODERN PHYSICS B
(2023)
Article
Thermodynamics
Sudhanshu Kumar, Krunal M. Gangawane, Hakan F. Oztop, Sibasish Panda
Summary: This research work presents a numerical investigation of magnetohydrodynamics (MHD) characteristics near-wall blockage due to double-diffusive convection (DDC) in a rectangular cavity. The results show that as the separation distance increases, heat and mass transfer rates enhance, while the increase in Hartmann number (Ha) results in a monotonic decrease in heat and mass transfer rates.
NUMERICAL HEAT TRANSFER PART A-APPLICATIONS
(2023)
Article
Metallurgy & Metallurgical Engineering
Mouna Ben Slama, Sami Chatti, Lioua Kolsi
Summary: Selective laser melting (SLM) can lead to detrimental porosity defects if improper processing parameters are used. Additional investigations are crucial to understand the effects of processing parameters and their interactions on the appearance of these defects. Research findings in the literature have mainly focused on qualitative exploration of parameters within small ranges. This study aims to fill the knowledge gap by examining the relationship between SLM parameters and the formation of porosity defects in 316L stainless steel (316L SS) across extended parameter intervals.
WELDING IN THE WORLD
(2023)
Article
Multidisciplinary Sciences
Walid Hassen, Nidhal Hnaien, Lotfi Ben Said, Faris Mohammed Albati, Badreddine Ayadi, Wajdi Rajhi, Lioua Kolsi
Summary: Due to rapid urbanization, industrial manufacturing plants have expanded quickly, resulting in the discharge of large amounts of pollutants into the environment, leading to deteriorating air quality and high health risks for city residents. The main objective of this study is to understand gas pollution dispersion in high-density urban environments, specifically in the Hail region of Saudi Arabia. Using Ansys Fluent 19.0 simulations, the study accurately reproduces the area's topography and examines factors such as building geometry and wind speed. The results reveal that gas pollution tends to accumulate within buildings at wind speeds above 7 m/s, resulting in significant concentrations.
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)
