Article
Mathematics, Applied
Rahmat Ellahi, Ahmed Zeeshan, Aamir Waheed, Nasir Shehzad, Sadiq M. Sait
Summary: The heat transfer study of carbon nanotubes-water nanofluid over a vertical truncated wavy cone is analyzed in this paper. It is found that the thickness of thermal boundary layer decreases with the increase of the volume fraction of carbon nanotubes. The results are in good accordance with the current literature.
MATHEMATICAL METHODS IN THE APPLIED SCIENCES
(2023)
Article
Mechanics
M. S. Asmadi, R. Md. Kasmani, Z. Siri, H. Saleh
Summary: This study investigates natural convection heat transfer inside a U-shaped enclosure using copper-alumina/water hybrid nanofluid with various thermal profiles. The results show that constant heating profile has the best heat dissipation performance, while sinusoidal thermal profile performed the worst.
Article
Thermodynamics
Ammar Abdulkadhim, Isam Mejbel Abed, Nejla Mahjoub Said
Summary: This study experimentally investigates the natural convection heat transfer in a three-dimensional I-shaped enclosure with wavy-walled and inner circular pipe. One layer is filled with Al2O3-water nanofluid while the other layer is filled with nanofluid/porous medium. The thermophysical properties of the nanofluid are measured, including thermal conductivity, viscosity, and density. The experimental results show good agreement with the calculated properties based on theoretical models within the studied nanofluid concentrations. Thermocouples are installed to measure the temperature, and magnetic fields are applied to observe the slight increase in temperature. It is also found that increasing the hot side wavy-walled temperature leads to an increase in the temperature difference in the nanofluid-porous region and the nanofluid region.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2023)
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
Mechanics
Surabhi Nishad, Rama Bhargava, Ameeya Kumar Nayak, Bernhard Weigand
Summary: Energy flux analysis of power-law fluid is a novel contribution to recent developments in computational fluid dynamics. The study investigates the influence of double diffusive effect on unsteady two-dimensional flow inside a complex enclosure and proposes a method for optimizing heat transfer rate. By comparing the computational time and accuracy of the finite volume method and element-free Galerkin technique, the study obtains results such as streamlines, isotherms, isoconcentrations, average Nusselt number, Sherwood number, etc., and analyzes the impact of various parameters. In addition, the study employs a mesh-free approach, providing a new method for further analysis of elliptical/semi-elliptical structures.
Article
Thermodynamics
Imtiaz Ali Shah, S. Bilal, Taseer Muhammad, Sayed M. Eldin
Summary: The prime motive of this case study is to investigate the enhancement in flow and thermal properties of water by adding carbon nanotubes and ferrite particles. A hexagonal enclosure with fillets at boundaries is considered for its physical significance in multiple heat exchange systems. The physical impact of a horizontal magnetic field and the adjustment of a heat circular cylinder are employed. The problem is formulated with necessary assumptions and boundary constraints in a dimensionless format. Thermophysical relations are utilized to explain the behavior of the distributions. Finite Element Method (FEM) is used to solve the modelled problem and the results are presented through snapshots and tables. The comparison of single and muti walled carbon nanotubes shows the rising trend of the velocity field in the hydrodynamic case compared to the hydromagnetic case. The heat transfer rate is found to be higher in the Fe3O4/MWCNT/water hybrid nanofluid. Results and code validation tests are conducted to ensure the credibility of the work.
CASE STUDIES IN THERMAL ENGINEERING
(2023)
Article
Thermodynamics
Khalil Ur Rehman, Wasfi Shatanawi, Haitham M. S. Bahaidarah, Safdar Abbas, A. U. Khan
Summary: This study numerically investigates the natural convection nanofluid flow in a partially heated rectangular enclosure. An inclined magnetic field is externally applied for better novelty. Wavy heated rods are installed at both the bottom and upper walls of the enclosure. Copper-Oxide (CuO) nanoparticles are suspended in the flow field. The flow characteristics are examined using the finite element method, considering the Hartmann number and angle of inclination as the flow-affecting parameters. The results show that the Nusselt number at the upper heated sinusoidal rod exhibits a higher magnitude compared to the lower heated corrugated rod for increasing values of the Hartmann number.
CASE STUDIES IN THERMAL ENGINEERING
(2023)
Article
Physics, Multidisciplinary
Muhammad Arshad Siddiqui, Ziafat Mehmood, Arshad Riaz, Dianchen Lu
Summary: This study presents computational simulation of natural convective energy transport through copper-based nanofluid in a isosceles triangular conduit in the presence of a magnetic field and energy source/sink. The results show that reduction in heat transport occurs due to magnetic force, and conduction and convection regimes vary for different Rayleigh numbers.
Article
Thermodynamics
Amin Kardgar
Summary: The study investigated conjugate heat transfer of natural convection and entropy generation of nanofluid in an inclined square cavity enclosure with an external magnetic field. The findings showed that increasing nanoparticle volume fraction, inclination angle, Ra number, and solid to fluid conductivity ratio could lead to different effects on heat transfer and entropy generation in the system. The study provides valuable insights into the behavior of nanofluid flow and heat transfer in the presence of an external magnetic field.
INTERNATIONAL JOURNAL OF NUMERICAL METHODS FOR HEAT & FLUID FLOW
(2021)
Article
Mechanics
Dipak Kumar Mandal, Nirmalendu Biswas, Nirmal K. Manna, Dilip Kumar Gayen, Rama Subba Reddy Gorla, Ali J. Chamkha
Summary: In this work, the numerical exploration of thermofluidic transport process in an M-shaped enclosure filled with permeable material and suspended with Al2O3-Cu hybrid nanoparticles is conducted. The impact of geometric parameters on thermal performance is analyzed, and an artificial neural network technique is implemented for prediction. The results reveal the importance of sidewall inclination and top triangular undulation in modulating thermo-flow physics.
Article
Mathematics, Applied
M. D. Alsulami, R. Naveen Kumar, R. J. Punith Gowda, B. C. Prasannakumara
Summary: The study investigates the heat transport properties under the lack of local thermal equilibrium conditions using a simplified mathematical model. The results suggest that the LTNE model yields two distinct primary thermal gradients between the fluid phase and the solid phase. The impact of different parameters on the velocity and thermal performance of non-Newtonian fluid flow containing Ti6Al4V and AA7075 nanoparticles in a porous media with magnetic effect is discussed.
ZAMM-ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND MECHANIK
(2023)
Article
Thermodynamics
M. Anil Kumar, Y. Dharmendar Reddy, V. Srinivasa Rao, B. Shankar Goud
Summary: A numerical model was used to investigate the flow and heat transfer of nanofluids from an infinite vertical plate in the presence of a magnetic field, thermal radiation, and viscous dissipation. The results showed that velocity and temperature distributions enhance with increasing radiation parameter value. These simulations are relevant for the processing of magnetic nanomaterials in the chemical industry and metallurgy sector.
CASE STUDIES IN THERMAL ENGINEERING
(2021)
Article
Thermodynamics
Shantanu Dutta, Sukumar Pati, Laszlo Baranyi
Summary: The study shows that the average Nusselt number increases with the volume fraction of nanoparticles and decreases with the Hartmann number. In addition to the influence of fluid properties and external conditions, the geometric variation of the enclosure volume also plays a role in altering the heat transfer rate.
CASE STUDIES IN THERMAL ENGINEERING
(2021)
Article
Multidisciplinary Sciences
Muhammad Bilal, Hamna Arshad, Muhammad Ramzan, Zahir Shah, Poom Kumam
Summary: This research focuses on investigating the thermal performance and temperature distribution of a hybrid nanofluid in a horizontal channel through numerical simulations and experiments. The results demonstrate that the hybrid nanofluid exhibits a more significant thermal enhancement compared to a simple nanofluid, with single-wall nanotubes having a greater impact on temperature.
SCIENTIFIC REPORTS
(2021)
Article
Multidisciplinary Sciences
Tamour Zubair, Muhammad Usman, Kottakkaran Sooppy Nisar, Ilyas Khan, Madiha Ghamkhar, Muhammad Ahmad
Summary: This study examines the application of fractional fluid models in nanofluid flow using numerical methods. The effects of free convection on an isothermal vertical sheet are investigated, taking into account the impact of chemical reactions. Fractional differential equations are used to describe the governing flow equations, and changes in parameters result in variations in concentration, velocity, and temperature profiles.
Article
Mathematics, Applied
Jaouad Danane, Zakia Hammouch, Karam Allali, Saima Rashid, Jagdev Singh
Summary: This paper studies a mathematical model of COVID-19 dynamics, taking into account government action and individual reaction. Numerical simulations show that government action and individual risk awareness effectively reduce the spread of infection, and the use of fractional derivatives speeds up the convergence of the infection to a steady state.
MATHEMATICAL METHODS IN THE APPLIED SCIENCES
(2023)
Article
Engineering, Marine
Saima Rashid, Rehana Ashraf, Zakia Hammouch
Summary: This study uses a semi-analytical method called homotopy perturbation transform method (HPTM) to obtain numerical results of nonlinear dispersive and fifth order KdV models in order to investigate the behavior of magneto-acoustic waves in plasma with fuzziness. The method is connected with fuzzy generalized integral transform and HPTM. The study also presents two new results for fuzzy generalized integral transformation involving fuzzy partial gH-derivatives. Illustrative examples are provided to demonstrate the effectiveness and superiority of the proposed method.
JOURNAL OF OCEAN ENGINEERING AND SCIENCE
(2023)
Article
Thermodynamics
Syed Saqib Shah, Hakan F. Oztop, Rizwan Ul-Haq, Nidal Abu-Hamdeh
Summary: This paper analyzes the buoyancy flow, mass and heat transfer in a coaxial duct under the Soret and Dufour effect. The combined effects of various parameters on natural convection are studied using a numerical approach. The results show that the Lewis number has a significant impact on mass transfer, while the buoyancy ratio parameter decreases the average rate of heat flow and increases mass transfer.
INTERNATIONAL JOURNAL OF NUMERICAL METHODS FOR HEAT & FLUID FLOW
(2023)
Article
Engineering, Multidisciplinary
Bushra Ishtiaq, Ahmed. M. Zidan, Sohail Nadeem, Mohammed Kbiri Alaoui
Summary: This article presents a comparative study of magnetohydrodynamics stagnant point flow in hybrid nanofluid using the extended versions of the Yamada-Ota model and Xue model. The study considers a time-dependent and thermally radiative two-dimensional flow with a stretchable/shrinking permeable sheet. The hybrid nanofluid is formulated by suspending Aluminum Oxide Al2O3 and Copper Cu nanoparticles in water. The nonlinear dimensionless system of ordinary differential equations is solved numerically using the bvp4c methodology. The study finds that the heat transfer rate is higher in the Yamada-Ota model compared to the Xue model, and increasing the stretching parameter enhances the velocity field but deteriorates the temperature distribution.
AIN SHAMS ENGINEERING JOURNAL
(2023)
Article
Mathematics, Applied
Nadeem Abbas, Sohail Nadeem, Wasfi Shatanawi
Summary: This study presents a numerical analysis of MHD 3D second grade fluid over slendering stretching sheet, with considerations of heat generation and thermal radiation impacts. The problem is mathematically stated as PDEs and transformed to nonlinear ODEs using appropriate similarity variables. The solutions are computed using MATLAB bvp4c function and the impacts of involving parameters on velocity and temperature are analyzed. The results show the effects of various parameters on skin friction and Nusselt number.
ZAMM-ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND MECHANIK
(2023)
Article
Mathematics, Applied
Sohail Nadeem, Salman Akhtar, Nevzat Akkurt, Anber Saleem, Shahah Almutairi, Hassan Ali Ghazwani
Summary: This study mathematically investigates the heat and mass transfer during the peristaltic flow of a non-Newtonian Jeffrey fluid inside an elliptic cross-section duct. The analysis considers constant heat absorption and provides a descriptive assessment of the heat and mass transfer. Exact solutions are obtained using a polynomial solution technique for the dimensionless partial differential equations in the problem. A purposeful graphical assessment is provided for the final mathematical results. Velocity and temperature profiles reach their highest values in the core region of the duct and gradually decrease towards the duct boundaries.
ZAMM-ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND MECHANIK
(2023)
Article
Physics, Multidisciplinary
Mirza Naveed Jahangeer Baig, Nadeem Salamat, Faisal Z. Duraihem, Salman Akhtar, Sohail Nadeem, Jehad Alzabut, Salman Saleem
Summary: This study mathematically models the stagnation point flow over a heated stretching cylinder using the phase flow approach. The interaction between impinging stagnation flow and flow due to the stretching surface of the cylinder is thoroughly interpreted. Exact analytical solutions are computed and evaluated graphically. Heat transport analysis and Nusselt number interpretation are incorporated. The results show a dominant impinging stagnation flow for higher oncoming flow pressure and lower stretching velocity of the cylinder.
CHINESE JOURNAL OF PHYSICS
(2023)
Article
Physics, Applied
Sohail Nadeem, Bushra Ishtiaq, Nevzat Akkurt, Hassan Ali Ghazwani
Summary: This study focuses on the entropy analysis of a hybrid nanofluid in stagnant point flow. Nonlinear dimensionless ordinary differential equations are obtained through appropriate similarity transformations. The results show that the mixed convection parameter has a significant impact on the velocity field, entropy generation, and induced magnetic field, and both entropy and heat transfer rate increase with the increase of mixed convection parameter.
INTERNATIONAL JOURNAL OF MODERN PHYSICS B
(2023)
Article
Physics, Applied
Syed Saqib Shah, Rizwan ul Haq, Hakan F. Oztop, Ali Raza
Summary: The study examines the influence of Magnetohydrodynamics (MHD) on the fluid in channel flow when a thin needle is present. A computational analysis is conducted to investigate the effects of inlet/outlet conditions with a curvilinear shaped body inserted in the channel. By using suitable dimensionless variables, the governing equations are transformed and various parameters are simulated to observe their impact on streamlines, isotherms, and temperature distribution at the mean position. The results show that Reynolds number, Richardson number, magnetic hydrodynamic, needle size and state all affect the local Nusselt number at the mean position.
INTERNATIONAL JOURNAL OF MODERN PHYSICS B
(2023)
Article
Engineering, Multidisciplinary
Sohail Nadeem, Shahbaz Ali, Nevzat Akkurt, Mohamed Bechir Ben Hamida, Shahah Almutairi, Hassan Ali Ghazwani, Sayed M. Eldin, Zareen A. Khan, A. S. Al-Shafay
Summary: This paper presents a comprehensive study on the mathematical modelling and numerical simulation of non-Newtonian blood flow in an idealized stenosed artery. The results show that the non-Newtonian nature of the fluid model significantly influences flow dynamics, with a greater degree of stenosis leading to higher velocity and pressure drop. Wall shear is substantially larger in stenotic passages, and the severity of stenosis is directly related to this increasing behavior.
ALEXANDRIA ENGINEERING JOURNAL
(2023)
Article
Thermodynamics
Sohail Nadeem, Shahbaz Ali, Jehad Alzabut, Mohamed Bechir Ben Hamida, Sayed M. Eldin
Summary: This study investigates the influence of hybrid nano-fluid on heat transport in a semi-annular channel using numerical methods. The hybrid nano-fluid consists of a liquid water with a suspension of SWCNT and MWCNT. Constant heat fluxes are applied to the channel walls. The finite volume approach is used to solve the governing equations. The results show that heat transport decreases as the volume fraction of MWCNT increases. The heat transfer from the walls to the fluid is affected by the curvature of the walls. The study provides velocity contours, isotherms, and local Nusselt number distributions for certain volume fractions of nanoparticles. It is discovered that walls with smaller curvature have stronger convection heat transfer. The pressure increases with the increase of nanoparticle volume percentage.
CASE STUDIES IN THERMAL ENGINEERING
(2023)
Article
Thermodynamics
S. Nadeem, R. Akber, H. A. Ghazwani, J. Alzabut
Summary: This study examines the behavior of steady and incompressible magnetohydrodynamics fluid flow with sinusoidal walls in a square cavity. The finite element method is used to numerically model the flow and heat transfer, resulting in temperature and velocity profiles. The study finds that the temperature and velocity exhibit good convergence for various parameter values. The significant impact of heat transfer rate on the results is also discussed.
NUMERICAL HEAT TRANSFER PART A-APPLICATIONS
(2023)
Article
Materials Science, Multidisciplinary
S. Nadeem, Bushra Ishtiaq, Jehad Alzabut, Hassan A. Ghazwani, Ahmad M. Hassan
Summary: This study compares the time-dependent flow of a micropolar fluid between a linear stretching sheet and an exponential stretching sheet. It is found that the exponential stretching sheet provides more consequential results compared to the linear stretching sheet. Additionally, the material parameter shows an increase in the velocity field for both types of sheets.
RESULTS IN PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Jehad Alzabut, Sohail Nadeem, Sumaira Noor, Sayed M. Eldin
Summary: This article investigates the modeling and numerical simulation of Magnetohydrodynamic (MHD) buoyancy driven convection flow in a differentially heated, square enclosure. Numerical solutions are computed for different values of Rayleigh number ranging 103 < Ra < 107 and Hartmann number ranging 0 < Ha < 40. Comportment of MHD free convection heat flow from transient to steady state is numerically examined for a period of 0 to 1 s. It is seen that with increasing values of Rayleigh number there is increase in local Nusselt number distribution on heated side of the cavity, while velocity distribution in the flow domain decreases with increasing Hartmann number.
RESULTS IN PHYSICS
(2023)
Article
Mathematics, Applied
K. Karthikeyan, G. S. Murugapandian, Z. Hammouch
Summary: This paper investigates the existence and uniqueness of mild solutions for fractional impulsive differential systems of the Sobolev type with fractional order nonlocal conditions using the monotone iterative technique in conjunction with the lower and upper solution techniques. Noncompactness estimates and the generalized Gronwall inequality are used to obtain the sufficient requirements.
MATHEMATICAL SCIENCES
(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)
