Article
Mathematics
Lioua Kolsi, Fatih Selimefendigil, Lotfi Ben Said, Abdelhakim Mesloub, Faisal Alresheedi
Summary: The study analyzed the forced convection of non-Newtonian nanofluid in a backward-facing flow system under the influence of a magnetic field and double rotating cylinders, showing significant effects on convective heat transfer and flow features. The presence of rotating double cylinders created a complex flow field with multiple recirculation regions, while the magnetic field helped suppress large vortices behind the step. The direction of rotation of the cylinders and the strength of the magnetic field had varying impacts on heat transfer enhancement and flow behavior.
Article
Mathematics
Badreddine Ayadi, Fatih Selimefendigil, Faisal Alresheedi, Lioua Kolsi, Walid Aich, Lotfi Ben Said
Summary: The study numerically evaluated the cooling performance of jet impinging hybrid nanofluid on a rotating hot circular cylinder under the influence of multiple magnetic fields using the finite element method. It was found that the rotation of the cylinder significantly affected heat transfer, while variations in magnetic field strength led to changes in the average Nu value. The distance between jets and size of the cylinder were important factors in flow dynamics and heat transfer performance.
Article
Thermodynamics
Anamika Maurya, Naveen Tiwari, R. P. Chhabra
Summary: The study explores the combined impact of power-law rheology and isothermal rotating cylinder on flow and heat transfer characteristics in a T-channel, showing that the rotating cylinder can manipulate momentum and thermal boundary layers. Factors such as rotational velocity and power-law flow index significantly affect the critical Reynolds number for various branches, with hydrodynamic forces exerted over the cylinder surface showing a strong relationship with cylinder rotation. The Nusselt number values are observed to vary with rotational velocity, direction of rotation, fluid power-law index, Reynolds and Prandtl numbers.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2021)
Article
Green & Sustainable Science & Technology
Fatih Selimefendigil, Hakan F. Oztop, Ali J. Chamkha
Summary: The study shows that the increase in average Nu number with Reynolds number depends on the power law index. The magnetic field strength and inclination can influence the size and number of vortices in the magnetic field. The aspect ratio of the curved wall has a slight impact on the flow field, while higher solid particle volume fraction and smaller particle size can increase the average Nu number.
Article
Engineering, Mechanical
Pooja Thakur, Naveen Tiwari, R. P. Chhabra
Summary: In this study, experiments were conducted to observe flow transitions of a rotating cylinder in shear-thinning fluids under different conditions, revealing critical values for Reynolds number, rotational velocity, and power-law index, as well as their nonmonotonic relationships. Additionally, it was found that increasing rotational velocity at a specific Reynolds number can suppress vortex formation in shear-thinning fluids, and the lift coefficient oscillates in unsteady flow regimes, with both amplitude and Strouhal number increasing with Reynolds number. The results highlight the complex interplay between kinematic and rheological parameters in non-Newtonian fluids at high Reynolds numbers, complementing existing low Reynolds number data.
JOURNAL OF FLUIDS ENGINEERING-TRANSACTIONS OF THE ASME
(2021)
Article
Engineering, Multidisciplinary
Imtiaz Ali Shah, Sardar Bilal, Ali Akgul, Mohamed Omri, Jamel Bouslimi, Noor Zeb Khan
Summary: The selection of appropriate geometrical characteristics of enclosure has a significant impact on the performance of thermal engineering processes and devices. This study investigates the thermal characteristics of power-law liquids and analyzes the influence of physical parameters on heat transfer.
ALEXANDRIA ENGINEERING JOURNAL
(2022)
Article
Mathematics
Jifeng Cui, Umer Farooq, Ahmed Jan, Murtada K. Elbashir, Waseem Asghar Khan, Mogtaba Mohammed, Ziyad Ali Alhussain, Jamshaid Ul Rahman
Summary: The practice of flowing effort is widely used in various industries, especially in nutrition production. This research explores the unique characteristics of circular cylinder stretching in the axial direction under the influence of Sisko fluid. By analyzing numerically, it is found that fluid velocity increases with material and curvature parameters, leading to improved heat transfer.
JOURNAL OF MATHEMATICS
(2021)
Article
Mathematics
Bagh Ali, N. Ameer Ahammad, Windarto, Abayomi S. Oke, Nehad Ali Shah, Jae Dong Chung
Summary: This study investigated the thermodynamics of a rotating dusty Maxwell water-based nanofluid with suspended dust particles and explored the effects of increased volume fraction of TiO2 particles and dust on fluid dynamics. By using appropriate similarity transformations, the governing PDEs for both fluid and dusty-phase models were transformed into non-linear linked non-dimensional ODEs. The bvp4c technique in MATLAB was employed to obtain graphical results. The magnitude of primary and secondary velocities in both phases decreased with an increase in dust particle volume concentration, Lorentz force, rotating, and Maxwell fluid parameters. The temperature variation in both dust and nanofluid phases was influenced by the increased strength of dust particles and TiO2.
Article
Mechanics
Shrikant Gandharv, P. Kaushik
Summary: Exploiting secondary velocities produced by Coriolis forces in Lab-on-CD systems is key to achieving better transport in pharmaceutical and biomedical applications. We explore the transient behavior of velocities in rotating microchannels aided by a grafted polyelectrolyte layer (a soft layer). The size of the polyelectrolyte layer grafted to the walls aids in better control of the flow velocities and oscillations.
Article
Multidisciplinary Sciences
Bai Yu, Muhammad Ramzan, Saima Riasat, Seifedine Kadry, Yu-Ming Chu, M. Y. Malik
Summary: The study investigates the flow of Ostwald-de-Waele nanofluid past a rotating disk in a porous medium with a melting heat transfer phenomenon. Results indicate that increasing surface catalyzed parameter effectively reduces thermal profile, and the power-law index has a more significant impact on fluid flow and thermal distribution.
SCIENTIFIC REPORTS
(2021)
Article
Materials Science, Multidisciplinary
Sardar Bilal, Noor Zeb Khan, Imtiaz Ali Shah, Jan Awrejcewicz, Ali Akgul, Muhammad Bilal Riaz
Summary: This study focuses on improving heat transfer characteristics in two-dimensional closed domains by placing cold cylinders. The placement of cold cylinders is found to be the most effective technique for enhancing heat transfer rate and reducing waste heat generation. The research analyzes the heat and flow characteristics of non-linear fluid in a square enclosure with the adjustment of the cold cylinder. Numerical computations and graphical projections are used to present the results.
Article
Physics, Multidisciplinary
Rashid Mahmood, Afraz Hussain Majeed, Muhammad Tahir, Imran Saddique, Nawaf N. Hamadneh, Ilyas Khan, Asif Mehmood
Summary: This numerical study investigates the steady flow of incompressible non-Newtonian fluids in a channel with static obstacles. Different cases, including circular and semicircular obstacles, are considered to analyze the impact of power-law index on drag and lift coefficients.
FRONTIERS IN PHYSICS
(2022)
Article
Physics, Mathematical
Ayele Tulu
Summary: This study aims to investigate MHD micropolar nanofluid flow past a radially stretchable rotating disk using the Cattaneo-Christov non-Fourier heat and non-Fick mass flux model. The governing equations are transformed into dimensionless ODEs and solved using the SLLM method. The results reveal the influence of various parameters on flow fields and engineering quantities, showing that radial stretching improves the cooling process and microrotation viscosity affects the radial velocity profile and kinetic energy. The study is novel in considering microscopic effects and the effect of radial stretching on micropolar nanofluid flow.
ADVANCES IN MATHEMATICAL PHYSICS
(2023)
Article
Mathematics, Applied
Hsueh-Chen Lee
Summary: This paper presents a least-squares finite element method for power-law fluid, studying the flow of non-Newtonian fluids through an unconfined square cylinder symmetrically placed in a two-dimensional channel. The method is proven effective and numerical results are shown to be consistent with theoretical estimates.
JOURNAL OF MATHEMATICAL ANALYSIS AND APPLICATIONS
(2021)
Article
Mechanics
Gholamreza Imani, Mohsen Mozafari-Shamsi
Summary: This paper uses a multiple-relaxation-time-lattice Boltzmann method to simulate the fluid flow through and around a rotating porous circular cylinder in uniform flow. The effects of Darcy number, velocity ratio, and Reynolds number on the Magnus lift and flow pattern are investigated. The results show the existence of a confined wake within the rotating porous cylinders at high Darcy numbers and velocity ratios of less than one, and the presence of the inverse Magnus effect at very high Darcy numbers.
Article
Energy & Fuels
Amin Shahsavar, Majid Jafari, Ighball Baniasad Askari, Fatih Selimefendigil
Summary: In this study, the influence of the number of ribs on the laminar forced convection flow of a silver/water-ethylene glycol nano-fluid in a rifled tube was investigated using the two-phase mixture model. The results showed that increasing the number of ribs was beneficial from the perspective of the first-law performance, but undesirable from the perspective of the second-law performance. It was also found that the rifled tube consistently outperformed the plain tube in terms of hydrothermal performance.
ENERGY SOURCES PART A-RECOVERY UTILIZATION AND ENVIRONMENTAL EFFECTS
(2023)
Article
Engineering, Multidisciplinary
Fatih Selimefendigil, Hakan F. Oztop, Lioua Kolsi, Mohamed Omri
Summary: The performance of a thermoelectric system in a chaotic channel is influenced by the type of fluid and Re number, resulting in varying power generation effects under different conditions. Nanofluids show potential in enhancing the power of the thermoelectric system, especially in channels containing shear thinning fluids.
ALEXANDRIA ENGINEERING JOURNAL
(2022)
Article
Energy & Fuels
Fatih Selimefendigil, Ceylin Sirin
Summary: The study investigates the impact of utilizing nano-enhanced thermal energy storage unit on the performance of a greenhouse dryer, comparing different types of greenhouse dryers. Results show that utilizing nano-enhanced modification significantly reduces drying time and improves energy efficiency.
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
(2022)
Article
Thermodynamics
Fatih Selimefendigil, Hakan F. Oztop
Summary: This study analyzes the effects of using a magnetic field and packed bed phase change material (PCM) system in a 3D cavity with ventilation ports on performance improvements during hybrid nanoliquid convection. Numerical simulations are conducted considering different inlet port locations and various parameters, showing that using PCM can enhance the average Nusselt number while the inlet port location has significant impacts on phase change dynamics and transition time.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Engineering, Mechanical
Fatih Selimefendigil, Hakan F. Oztop
Summary: The combined use of an elastic fin and magnetic field accelerates the phase change process dynamics, reducing the phase completion time and providing excellent control in a PCM-packed cylindrical reactor. The effects of different parameters, such as Reynolds number and magnetic field strength, on the phase change dynamics were explored, showing significant improvements in process acceleration and efficiency.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2022)
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%.
Review
Multidisciplinary Sciences
Fatih Selimefendigil, Gurel Senol, Hakan F. Oztop, Nidal H. Abu-Hamdeh
Summary: This review discusses the applications of non-Newtonian nanofluids for convection in cavities under a magnetic field. Convection in cavities is of great significance in thermal energy systems, with various applications in different processes. The review provides information on nanofluids and non-Newtonian fluids, and focuses on the thermal conductivity/viscosity, as well as the magnetohydrodynamic effects of non-Newtonian nanofluids. Different applications of vented cavities using nanofluid and magnetic field are explored. The review points out the gaps in current literature and discusses future trends.
Article
Multidisciplinary Sciences
Hakan F. Oztop, Omer Akbal, Fatih Selimefendigil, Nidal H. Abu-Hamdeh
Summary: Three-dimensional computational analysis investigates the melting time of PCM in a sinusoidal pipe inserted into another pipe. The study aims to control melting time through passive techniques by adjusting the geometrical parameter without extra energy consumption.
Article
Energy & Fuels
Fatih Selimefendigil, Furkan Dilbaz, Hakan F. Oztop
Summary: The thermal management of lithium-ion batteries is crucial for improving their performance and lifespan. This study proposes a novel cooling system using an inner cylinder and different-shaped nanoparticles as the cooling medium. Numerical analysis shows that both cooling media reduce the highest temperature and homogenize the temperatures in the battery as the Reynolds number increases. The utilization of a nanofluid containing cylindrical-shaped nanoparticles and a cylinder in the mini-channel proves to be an effective cooling system for battery thermal management.
Article
Thermodynamics
Fatih Selimefendigil, Hakan F. oeztop
Summary: The design of a cooling system for a curved conductive panel is developed using nano-enhanced multiple jet impingement. The study shows that the type of panel and operating parameters affect cooling performance and entropy generation. Adjustments in operating parameters can improve cooling effectiveness and reduce entropy generation.
NUMERICAL HEAT TRANSFER PART A-APPLICATIONS
(2023)
Article
Thermodynamics
Hakan F. Oztop, Fatih Selimefendigil, Hakan Cosanay, Nidal Abu-Hamdeh
Summary: In this study, the phase change process and convection inside an open cavity equipped with two different phase change materials (PCMs) were analyzed using the finite volume method with ANSYS Fluent. The analysis was conducted for different Grashof number values and it was found that the PC becomes faster when the object is closer to the exit in the fully open case. The partly open case results in higher thermal performance improvements, with a 94.5% increase in the average Nusselt number for PCM-18.
NUMERICAL HEAT TRANSFER PART A-APPLICATIONS
(2023)
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
Energy & Fuels
Hakan F. F. Oztop, Elanur Baki Sezgin
Summary: The use of containers with streamlined corners reduces the melting time of phase change materials (PCMs) under the same boundary conditions, serving as a passive control method to improve energy efficiency.
ENERGY SOURCES PART A-RECOVERY UTILIZATION AND ENVIRONMENTAL EFFECTS
(2023)
Article
Thermodynamics
Burak Kiyak, Hakan F. Oztop, I. Gokhan Aksoy
Summary: This study investigated the melting performance of phase change materials in a disk-shaped container with partial circular heating. The results showed that in partial heating cases, increasing the aspect ratio extended the melting time and decreased the liquid fraction.
NUMERICAL HEAT TRANSFER PART A-APPLICATIONS
(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
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)