Article
Engineering, Mechanical
L. L. X. Augusto, M. H. Takahama, C. O. R. Negrao, T. Cousseau
Summary: This paper presents a numerical investigation of non-isothermal grease flow in labyrinth seals, considering the effects of heat transfer and viscous thermal dissipation on mechanical losses. The study found that heat transfer and viscous dissipation, which increase with shaft rotational speed, raise flow temperature, reducing grease viscosity and friction losses. Additionally, the influence of labyrinth materials (steel and polymer) on heat loss and viscous losses was analyzed, with polymer labyrinth showing higher temperature levels due to lower thermal conductivity.
TRIBOLOGY INTERNATIONAL
(2021)
Article
Nanoscience & Nanotechnology
Youngsup Song, Shuai Gong, Geoffrey Vaartstra, Evelyn N. Wang
Summary: Boiling is a fundamental process in many applications where surfaces with microcavities or biphilic wettability can enhance heat transfer efficiency. This study investigated microtube structures to simultaneously enhance heat transfer coefficient and critical heat flux, achieving significant improvements compared to smooth surfaces. The combination of micropillars and microtubes further increased critical heat flux by separating nucleating bubbles and rewetting liquids.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Physics, Applied
N. Bhargavi, T. Poornima, Basma Souayeh
Summary: This paper explores the influence of conjugate heat transfer based on radiation and magnetohydrodynamic utilization. The research results have many applications in thermal engineering, heat exchangers, cooling phenomenon, magnetic cell separation, energy production, hyperthermia, etc. The effects of various fluid obeying parameters such as magnetic field, viscous dissipation, and heat generation on flow factors such as velocity and temperature are graphed and discussed in this paper.
INTERNATIONAL JOURNAL OF MODERN PHYSICS B
(2023)
Article
Energy & Fuels
Zahir Shah, Muhammad Rooman, Muhammad Asif Jan, Narcisa Vrinceanu, Wejdan Deebani, Meshal Shutaywi, Santiago Ferrandiz Bou
Summary: This study investigates the three-dimensional micropolar nanofluids of single and multi-walled carbon nanotubes dissolved in water and gasoline liquids for the first time. Results show that as the volume fraction increases, micro-rotational velocities also increase. Additionally, the impact of multi-walled CNTs is found to be more significant than that of single-walled CNTs.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2022)
Article
Energy & Fuels
Zahir Shah, Muhammad Rooman, Muhammad Asif Jan, Narcisa Vrinceanu, Wejdan Deebani, Meshal Shutaywi, Santiago Ferrandiz Bou
Summary: This article presents the first examination of three-dimensional micropolar nanofluids consisting of single and multi-walled carbon nanotubes dissolved in water and gasoline liquids. The study focuses on the classical Bodewadt flow and incorporates the Darcy-Forchheimer porous media. The energy equation, including convection, radiation, and viscous dissipation, is investigated. The flow field equations are transformed from partial differential equations to ordinary differential equations, and solutions are obtained using the bvp4c technique. Results show that an increase in volume fraction enhances micro-rotational velocities, and skin friction decreases with increasing porosity parameter and volume fraction. Multiple-walled CNTs have a more significant effect compared to single-walled CNTs, and gasoline oil exhibits a dominant trend when compared to water-based fluids.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2022)
Article
Engineering, Multidisciplinary
Wei-Feng Xia, M. Ijaz Khan, Sami Ullah Khan, Faisal Shah, M. Imran Khan
Summary: Due to improved thermophysical properties, nanofluids have diverse applications in industries, engineering, and biomedicine. Analysis of viscous nanofluid flow over a vertical plate subject to magnetic force reveals variations in velocity, temperature, and concentration distributions under different parameters.
AIN SHAMS ENGINEERING JOURNAL
(2021)
Article
Computer Science, Artificial Intelligence
Najiyah Safwa Khashi'ie, Nur Syahirah Wahid, Norihan Md Arifin, Ioan Pop
Summary: This paper investigates the MHD stagnation-point flow of Cu-Al2O3/H2O hybrid nanofluid on a convectively heated shrinking disk, taking into account suction, Joule heating, and viscous dissipation effects. Numerical solutions reveal the existence of two solutions, with the first solution being physically stable. The results show that an increase in suction and magnetic parameters enhances the heat transfer performance, while the Eckert and Biot numbers have no effect on the critical value. The temperature profile decreases with an increase in the velocity ratio parameter, Eckert and Biot numbers, while the velocity increases with an increase in the velocity ratio and magnetic parameters.
NEURAL COMPUTING & APPLICATIONS
(2022)
Article
Thermodynamics
Aamir Ali, A. Noreen, S. Saleem, A. F. Aljohani, M. Awais
Summary: The study investigates the influence of Cu-Al2O3MHD hybrid nanofluid on heat transfer and flow through mathematical modeling and computations, revealing a decrease in temperature and an increase in fluid velocity with increasing volume fraction. Additionally, the change in fluid temperature under heat source/sink conditions was examined.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2021)
Article
Engineering, Chemical
Amir Abbas, Mdi Begum Jeelani, Abeer S. Alnahdi, Asifa Ilyas
Summary: This study examines the behavior of magnetohydrodynamic Williamson nanofluid flow and heat transfer over a non-linear stretching sheet embedded in a porous medium. The influence of heat generation and viscous dissipation is taken into account. Through numerical calculations and physical reasoning, the distributions of velocity, temperature, and concentration are obtained and validated against existing solutions.
Article
Thermodynamics
Mair Khan, T. Salahuddin, Sadia Ayub, Mohamed Altanji
Summary: In the past few decades, studies on controlling irreversibility or entropy generation in fluid flow models have been of interest to scientists. This study analyzes the contribution of thermophysical properties, viscous dissipation, and solar radiation in the heat transfer of a fluid flow induced by a heated flat plate, both theoretically and numerically. The system consists of steady boundary layer flow of modified viscous fluid with temperature-dependent viscosity. Other fluid properties are assumed to be variable. The energy equation includes solar radiative heat flux and viscous dissipation effects. The governing equations are transformed into a system of ordinary differential equations using a similarity variable approach. Numerical solutions are obtained using the RK-five integator method with the shooting technique. The analysis of mean-flow and entropy profiles, along with physical reasoning, is presented in the last section. The study concludes that the concentration ratio variable has a positive effect on the irreversibility of the system.
THERMAL SCIENCE AND ENGINEERING PROGRESS
(2023)
Article
Multidisciplinary Sciences
Md Hasanuzzaman, Sathi Akter, Shanta Sharin, Md Mosharof Hossain, Akio Miyara, Md Amzad Hossain
Summary: This article investigates the effects of radiative and viscous dissipation on the transfer of unsteady magnetic-conductive heat-mass across a vertically porous sheet. The non-dimensional ODEs are numerically solved using the Finite Difference Method (FDM) in MATLAB software. The results show that the fluid temperature and velocity increase with higher Eckert numbers, while the velocity, concentration, and temperature distributions decrease with increasing values of the transpiration parameter. The numerical results are compared with a previously published paper and show excellent agreement.
Article
Thermodynamics
J. W. Elliott, M. T. Lebon, A. J. Robinson
Summary: Increasing power densities in modern CPUs have led to high temperature regions on the semiconductor die, affecting performance and reliability. A study on imposing a non-uniform heat transfer coefficient profile on the CPU's heat spreader surface showed that multi-objective optimization achieved the best heat transfer coefficient distribution, resulting in reduced temperature and temperature gradient across the heat source.
CASE STUDIES IN THERMAL ENGINEERING
(2022)
Article
Chemistry, Multidisciplinary
Xiaohui Lin, Weihuang Cai, Shaolei Huang, Sijie Zhu, Dongxu Zhang
Summary: This study designed efficient heat-dissipation schemes for a nucleic acid detector through simulation and experimental validation, ensuring the stability of nucleic acid detection process and the safety of electronic components.
APPLIED SCIENCES-BASEL
(2022)
Article
Mathematics
Zia Ullah, Musaad S. Aldhabani, Muhammad Adnan Qaiser
Summary: This study investigates the impact of viscous dissipation, Joule heating, and magnetohydrodynamics on a magnetized cylinder to insulate excessive heat. The complex equations are transformed and solved using non-dimensional representation, leading to computational answers for the related dimensionalized formulations.
Article
Computer Science, Interdisciplinary Applications
Ramesh B. Kudenatti, Noor E. Misbah, M. C. Bharathi
Summary: Numerical simulations are conducted to study forced convective heat transfer and boundary layer flow of non-Newtonian fluid over a moving wedge. The effects of Carreau fluid on velocity, heat transfer rate, and thicknesses are investigated. The simulations reveal both single and double solutions, with the first solutions being stable and the second solutions being time-amplified. Linear stability analysis is performed to identify which solutions can be practically simulated.
MATHEMATICS AND COMPUTERS IN SIMULATION
(2023)
Article
Construction & Building Technology
Yunus Emre Cetin, Mete Avci, Orhan Aydin
Summary: The study investigates the effect of air change rate on indoor particle dispersion and deposition in a ventilated room. Experimental and numerical analysis show that the contaminant level decreases with increasing air change rate for a constant particle flow rate, while the opposite trend is observed for a proportional particle flow rate.
INTERNATIONAL JOURNAL OF VENTILATION
(2022)
Article
Thermodynamics
Soner Birinci, Mehmet Saglam, Bugra Sarper, Orhan Aydin
Summary: This study investigates the effect of heaters' clearance on mixed convective cooling performance in a discretely heated horizontal duct. Results show that increasing the clearance can lead to a reduction in hot spot temperature and an improvement in the system's global conductance.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2021)
Article
Thermodynamics
Burak Markal, Ayse Candere, Mete Avci, Orhan Aydin
Summary: The combined influence of filling ratio, geometry, inclination angle, and heating power on heat transfer characteristics of pulsating heat pipes (PHPs) was investigated in this study, revealing the key roles of phase change phenomena and bubble dynamics in the thermal characteristics. It was concluded that non-uniform design can improve the operational performance of non-uniform PHPs by reducing the influence of gravity on the results.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2021)
Article
Thermodynamics
Burak Markal, Ayse Candan Candere, Mete Avci, Orhan Aydin
Summary: Experimental investigation on the effect of double cross sectional ratio on performance characteristics of pulsating heat pipes shows that novel gradually constricted geometry boosts flow circulation and maintains stable performance. The newly designed pulsating heat pipe demonstrates better thermal performance than the conventional design.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2021)
Article
Thermodynamics
Mehmet Tahir Erdinc, Arif Emre Aktas, Muhammet Nasif Kuru, Mehmet Bilgili, Orhan Aydin
Summary: This study investigated the thermo-hydraulic characteristics of circular and diamond shaped cross-sections in periodic flow using numerical methods and multi-objective genetic algorithm (MOGA) for optimization. The results showed that compared to circular geometries, the average Nusselt number of diamond shaped geometry increased by 10.11%, while pressure drop and volume decreased by 11.90% and 52.76%, respectively.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2021)
Article
Thermodynamics
Bugra Sarper, Soner Birinci, Mehmet Saglam, Orhan Aydin
Summary: This study investigates the optimum heat generation rate of local heating elements with different heat generation rates in a vertical duct through experimental and numerical studies. The results show that a lower heat generation rate of heating elements improves the cooling performance of the system.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2022)
Article
Thermodynamics
Burak Markal, Beyzanur Kul, Mete Avci, Ramazan Varol
Summary: This paper investigates the effect of gradually expanding flow passages on saturated flow boiling characteristics of micro pin fin heat sinks. The experimental results show that this design can significantly improve the two-phase heat transfer coefficient and suppress flow boiling instabilities.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Thermodynamics
Fatma Sahin, Ahmet Kaya, Erdem Alic, Orhan Aydin
Summary: This study investigates the effect of a mechanical agitator on heat transfer at pool boiling through experimental and numerical methods. The results show that increasing the number of agitator blades and reducing the distance between the agitator and the heater can significantly improve heat transfer efficiency.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2022)
Article
Thermodynamics
Melisa Albayrak, Bugra Sarper, Mehmet Saglam, Soner Birinci, Orhan Aydin
Summary: This study investigates the influence of the jet-to-cross flow velocity ratio on convective heat transfer and flow characteristics in a channel with discrete heating modules. The study reveals that as the velocity ratio increases, the jet flow becomes dominant, leading to an increase in convective heat transfer and thermal enhancement factor.
THERMAL SCIENCE AND ENGINEERING PROGRESS
(2023)
Article
Thermodynamics
M. Tahir Erdinc, Cagri Kutlu, Saban Unal, Orhan Aydin, Yuehong Su, Saffa Riffat
Summary: This study proposes a renewable energy sourced and high-efficiency heat pump system which utilizes dual thermal sources (air and solar) to provide a renewable heating solution. By incorporating a PV/T collector and ejector technology, the system can achieve higher performance and reduce the demand from the grid.
THERMAL SCIENCE AND ENGINEERING PROGRESS
(2023)
Article
Thermodynamics
M. Y. Yazici, M. Saglam, O. Aydin, M. Avci
Summary: The experimental study focuses on the melting heat transfer performance and energy storage efficiency of PCM/graphite matrix in a tube-in-shell setup for solar thermal energy storage and waste heat recovery applications. The inlet temperature of the heat transfer fluid had a significant impact on the total melting time. The results indicated that the PCM/graphite matrix showed remarkable effects on phase change heat transfer, with enhanced thermal conductivity and reduced melting time compared to conventional units.
THERMAL SCIENCE AND ENGINEERING PROGRESS
(2021)
Article
Engineering, Multidisciplinary
Yunus Emre Cetin, Mete Avci, Orhan Aydin
Summary: The study investigates the effect of air change rate on particle dispersion for different contaminant source positions through experimental and numerical methods. It is found that pollutants outside the main flow region lead to significantly higher concentration values, and increasing the air change rate can drastically reduce pollutant concentration in this region.
JOURNAL OF POLYTECHNIC-POLITEKNIK DERGISI
(2021)
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)
