Article
Thermodynamics
Ubaidullah Yashkun, Khairy Zaimi, Nor Ashikin Abu Bakar, Anuar Ishak, Ioan Pop
Summary: This study investigates the heat transfer characteristics of MHD hybrid nanofluid over a linear stretching and shrinking surface with suction and thermal radiation effects. The study finds that the heat transfer efficiency of the hybrid nanofluid is greater than the nanofluid, and dual solutions exist for a specific range of the stretching/shrinking parameter. Additionally, the skin friction coefficient and local Nusselt number increase with suction effect, and suction and thermal radiation widen the range of the stretching/shrinking parameter for which solutions exist.
INTERNATIONAL JOURNAL OF NUMERICAL METHODS FOR HEAT & FLUID FLOW
(2021)
Article
Mathematics, Applied
K. Veera Rddy, G. Venkata Ramana Reddy, Ali Akgul, Rabab Jarrar, Hussein Shanak, Jihad Asad
Summary: The dynamics of chemically reactive and thermally conducting Casson nanofluid flowing past an elongated sheet was investigated numerically in this study. It was found that increasing the visco-inelastic parameter and the magnetic parameter leads to a degradation of velocity profiles. Additionally, an increase in the magnetic parameter results in a decrease in the distribution of velocity. The effects of variable thermal conductivity and variable diffusion coefficient on temperature and concentration contours were also discussed. The boundary layer distributions deteriorate as the unsteadiness parameter is increased.
Article
Multidisciplinary Sciences
Anwar Saeed, Abdelaziz Alsubie, Poom Kumam, Saleem Nasir, Taza Gul, Wiyada Kumam
Summary: This study investigates heat transportation and irreversibility analysis for the flow of couple stress hybrid nanofluid over a stretching surface, with the innovative use of EMHD, viscous dissipation, Joule heating, and heat absorption in the transportation heat couple stress model. The mathematical model is applied for biological advantages, such as drug deliveries in human blood testing. The innovative homotopy analysis method (HAM) is used to solve the resulting nonlinear differential equations, with an emphasis on factors impacting fluid flow.
SCIENTIFIC REPORTS
(2021)
Article
Multidisciplinary Sciences
Umar Farooq, Madeeha Tahir, Hassan Waqas, Taseer Muhammad, Ahmad Alshehri, Muhammad Imran
Summary: This research investigates the three-dimensional flow of hybrid nanofluid and its heat and mass transfer enhancement mechanisms. The effects of homogeneous-heterogeneous processes and thermal radiation are considered. Numerical results show the effects of different controlling parameters on velocity, temperature, and concentration distribution.
SCIENTIFIC REPORTS
(2022)
Article
Thermodynamics
M. Riaz Khan, Mohamed Abdelghany Elkotb, R. T. Matoog, Nawal A. Alshehri, Mostafa A. H. Abdelmohimen
Summary: This article investigates the unsteady radiative two-dimensional stagnation point flow of a Casson fluid along a stretching and shrinking sheet, dependent on mixed convection, convective condition, and the slip condition. The study reveals that friction and heat transfer rates are influenced by various parameters, with heat generation parameter affecting the heat transfer rate. The research findings are deemed innovative and can pave the way for future analyses of non-Newtonian fluids.
CASE STUDIES IN THERMAL ENGINEERING
(2021)
Article
Multidisciplinary Sciences
U. S. Mahabaleshwar, T. Anusha, O. Anwar Beg, Dhananjay Yadav, Thongchai Botmart
Summary: This article theoretically examines the magnetohydrodynamic coating boundary layer flow of hybrid nanofluids in porous media, considering the presence of chemically reactive nanoparticles. The analysis reveals that magnetic field and wall solutal slip have significant effects on velocity and concentration distributions.
SCIENTIFIC REPORTS
(2022)
Article
Multidisciplinary Sciences
Fuzhang Wang, Shafiq Ahmad, Qasem Al Mdallal, Maha Alammari, Muhammad Naveed Khan, Aysha Rehman
Summary: This article mainly focuses on the influence of chemical reaction slip condition on the unsteady three-dimensional Maxwell bio-convective nanomaterial liquid flow towards an exponentially expanding surface. The study examines the changes in temperature, velocity, microorganism, and concentration field through numerical calculations and graphical evaluation. The results show that the involvement of unsteadiness parameter restricts the transition from laminar to turbulent flow, while the velocity slip parameter has a decreasing effect on velocity components.
SCIENTIFIC REPORTS
(2022)
Article
Engineering, Multidisciplinary
Taza Gul, Muhammad Rehman, Anwar Saeed, Imran Khan, Amir Khan, Saleem Nasir, Abdul Bariq
Summary: This study investigates a mathematical model of time-dependent thin-film flow of Carreau liquid over a stretching surface in the presence of couple stress and uniform magnetic field. The properties of heat and mass transport phenomena, including thermophoresis and Brownian motion, are studied. The numerical results show the effects of different physical factors on skin-friction coefficient, Nusselt number, Sherwood number, fluid velocity profile, thermal profile, and concentration profile.
MATHEMATICAL PROBLEMS IN ENGINEERING
(2021)
Article
Physics, Multidisciplinary
L. T. Benos, K. R. Nagaraju, U. S. Mahabaleshwar, M. S. Prasad, I. E. Sarris, G. Lorenzini
Summary: The paper investigates heat transfer in stretching and shrinking sheets with a sponge-like horizontal wall, considering Prandtl number, radiation, and external magnetic field effects. The Navier-Stokes equations are simplified to partial, and eventually ordinary differential equations, which are analytically solved. Results show that the thickness of the thermal boundary layer decreases with increasing transpiration, Chandrasekhar and Prandtl numbers, or decreasing radiation number, with different heat transfer characteristics between shrinking and stretching sheets.
CHINESE JOURNAL OF PHYSICS
(2021)
Article
Physics, Multidisciplinary
U. S. Mahabaleshwar, Emad H. Aly, T. Anusha
Summary: This article investigates the non-Newtonian MHD flow and heat transfer of copper-alumina/water hybrid nanofluid due to permeable stretching/shrinking surface with a full slip model. The system of nonlinear partial differential equations was transformed to a system of ordinary differential equations. The impact of various physical parameters on velocity and temperature distributions were discussed, and it was found that the temperature distribution and thermal boundary layer increase with the increase of certain parameters. Additionally, the velocities and temperatures of the nanofluid and hybrid nanofluid behave differently in stretching and shrinking cases. The findings have potential industrial and technological applications.
CHINESE JOURNAL OF PHYSICS
(2022)
Article
Mathematics, Applied
Bilal Ali, Mashael M. M. Albaidani, Sidra Jubair, Abdul Hamid Ganie, Shaimaa A. M. Abdelmohsen
Summary: The importance of convective heat transfer is intensified in various disciplines of modern engineering and technological development. This study focuses on developing a mathematical model for the 2D stagnation point flow of a heated stretchable sheet, considering nonlinear thermal radiation and a revised nanofluid model. Analysis includes the influence of Newtonian heating, MHD flow, and Brownian movement features. The nonlinear PDEs are modeled using boundary layer theory and converted into nonlinear ODEs using MATHEMATICA 11.0 programming. Graphical illustrations provide insights into the relevant flow parameters. This investigation greatly impacts engineering applications in geophysical and geothermal systems, storage devices, space science, and other disciplines.
ZAMM-ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND MECHANIK
(2023)
Article
Multidisciplinary Sciences
Abdullah Dawar, Zahir Shah, Hashim M. Alshehri, Saeed Islam, Poom Kumam
Summary: This study analyzes the magnetized and non-magnetized Casson fluid flow over a stratified stretching cylinder, presenting an analytical solution using the homotopy analysis method and showing the effects of various dimensionless factors on physical quantities and flow profiles. It has been shown that the behavior of streamlines and fluid velocity changes with the Casson parameter, with different patterns observed for magnetized and non-magnetized fluids.
SCIENTIFIC REPORTS
(2021)
Article
Chemistry, Analytical
Kolkar Nanjappa Sneha, Gadabanahalli Puttasiddappa Vanitha, Ulavathi Shettar Mahabaleshwar, David Laroze
Summary: This article describes the unsteady flow of a ternary hybrid nanofluid on a stretching surface with porous media. The flow process is evaluated using an analytical method, considering factors such as thermal radiation and couple stress.
Article
Multidisciplinary Sciences
Faisal Shahzad, Wasim Jamshed, Kottakkaran Sooppy Nisar, Nor Ain Azeany Mohd Nasir, Rabia Safdar, Abdel-Haleem Abdel-Aty, I. S. Yahia
Summary: The study focuses on MHD viscous Jeffrey heat transport flow past a permeable extending sheet, using Alumina nanoparticles immersed in sodium alginate as the base fluid. The results indicate that viscous dissipation, heat generation, and Ohmic heating affect the fluid properties, while parameters like porosity, volume fraction of nanoparticles, and Deborah number impact heat transfer and fluid velocity.
SCIENTIFIC REPORTS
(2022)
Article
Mathematics, Applied
Adeel Ahmad, Airal Ishaq, Maria Athar, Junaid Anjum, Rab Nawaz
Summary: In this study, the unsteady flow of a micropolar fluid past a magnetized stretchable/shrinkable sheet is investigated. The effects of magnetic field, moving slit, and various parameters on the fluid's velocity, magnetic, and microrotation profiles are analyzed. Ordinary differential equations are derived from the partial differential equations defining the problem using the Blasius-Rayleigh-Stokes variable. The shooting method is used to solve the transformed set of equations and dual solutions are obtained. The findings demonstrate that skin friction decreases with increasing values of the microrotation parameter and magnetic interaction parameter, and the magnetic interaction parameter enhances the microrotation of molecules. This study provides valuable insights into the behavior of unsteady flows in micropolar fluids and the impact of various parameters on dual solutions.
ZAMM-ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND MECHANIK
(2023)
Article
Energy & Fuels
Pothala Jayalakshmi, Mopuri Obulesu, Charan Kumar Ganteda, Malaraju Changal Raju, Sibyala Vijayakumar Varma, Giulio Lorenzini
Summary: The present study investigates the steady three-dimensional flow of a Sisko fluid over a bidirectional stretching sheet under the influence of Lorentz force. Heat transfer effects have been studied for constant heat flux and Newtonian heating systems. The effects of controlling parameters on flow and derived quantities are presented in graphs and tables. Numerical benchmarks are used to characterize the effects of skin friction and heat transfer rates. It is noticed that in the case of Newtonian heating, the rate of heat transfer is higher than that in the constant heat flux case. As the stretching parameter increases, the fluid temperature decreases in both Newtonian heating and constant heat flux. Successive over (under) relaxation (SOR) approaches significantly improve the convergence speed and stability of the SRM system. The current findings strongly agree with earlier studies in the case of Newtonian fluid when the magnetic field is absent.
Article
Energy & Fuels
Javali Kotresh Madhukesh, Ioannis E. Sarris, Ballajja Chandrappa Prasannakumara, Amal Abdulrahman
Summary: This study comprehensively investigates the thermal performance of a ternary hybrid nanofluid flowing in a permeable inclined cylinder/plate system, focusing on the effects of inclined geometry, permeable medium, and heat source/sink. A mathematical model is developed and numerically solved using the RKF45 method and shooting technique. The findings provide insights into the behavior of ternary nanofluids in such systems and discuss important engineering coefficients. Results show that porous constraint improves thermal distribution but decreases velocity, heat-source sink improves temperature profile, and plate geometry outperforms cylinder geometry in the presence of solid volume fraction.
Article
Multidisciplinary Sciences
Amir Abbas, Ioannis E. Sarris, Muhammad Ashraf, Kaouther Ghachem, Nidhal Hnaien, Badr M. Alshammari
Summary: The study investigates the effects of reduced gravity and solar radiation on MHD fluid flow and heat transfer around a solid sphere in a porous medium. A model in dimensionless form is solved using the finite difference method and solutions for velocity distribution and temperature field are depicted in graphs and tables. The results show that velocity increases with reduced gravity and solar radiation parameters, but decreases with the Prandtl number, magnetic field parameter, and porous medium parameter. Temperature decreases with the reduced gravity parameter and the Prandtl number, but increases with the magnetic field, porous medium, and radiation parameters at all positions on the surface of the sphere. A comparison with published results is done to confirm the accuracy of the numerical model.
Article
Multidisciplinary Sciences
R. S. Varun Kumar, Ioannis E. Sarris, G. Sowmya, Amal Abdulrahman
Summary: The present investigation focuses on analyzing the temperature distribution in a conductive-radiative rectangular profiled annular fin with internal heat generation. The study takes into account the nonlinear variation of thermal conductivity and heat transfer coefficient governed by the power law. The analytical approximation for the non-dimensional temperature profile is obtained using the differential transform method (DTM)-Pade approximant. The impact of thermal parameters on the temperature field and thermal stress is elaborated with graphs.
Article
Multidisciplinary Sciences
Amir Abbas, Muhammad Ashraf, Ioannis E. E. Sarris, Kaouther Ghachem, Taher Labidi, Lioua Kolsi, Hafeez Ahmad
Summary: The current study focuses on the effects of reduced gravity and radiation on magnetohydrodynamic natural convection past a solid sphere. A mathematical model based on coupled and nonlinear partial differential equations is developed. The model is then transformed into dimensionless form using appropriate scaling variables. The governing equations are solved using the finite difference method and the velocity and temperature profiles, as well as the skin friction coefficient and Nusselt number, are determined. The results are presented graphically and in tabular form. The verification of the numerical model shows good agreement with the literature. The main objective of this investigation is to analyze the influence of buoyancy force caused by density variation on natural convective heat transfer past a solid sphere. The results reveal that the velocity increases with the reduced gravity parameter and solar radiation, but decreases with the Prandtl number and magnetic field parameter. Moreover, the temperature increases with solar radiation and magnetic field, but decreases with the reduced gravity parameter and Prandtl number.
Article
Physics, Fluids & Plasmas
George Sofiadis, Ioannis E. Sarris, Alexandros Alexakis
Summary: We show that the inverse cascade of two-dimensional turbulence can exhibit a lack of self-similarity and intermittency when the energy injection is constrained within a fractal set of dimension less than two. Numerical simulations of two-dimensional turbulence with different forcing functions and fractal dimensions are conducted, demonstrating the loss of self-similarity and the emergence of intermittency as the fractal dimension decreases. This model serves as a valuable example to understand and test multifractal models of turbulence.
PHYSICAL REVIEW FLUIDS
(2023)
Article
Mathematics
R. S. Varun Kumar, M. D. Alsulami, I. E. Sarris, G. Sowmya, Fehmi Gamaoun
Summary: This research investigates the stable, one-dimensional thermal distribution and heat transfer of a wavy fin, considering convective effects and temperature-dependent thermal conductivity. A novel machine learning strategy based on a neural network with backpropagated Levenberg-Marquardt algorithm is proposed to interpret the heat transfer analysis. The effectiveness of the proposed strategy is validated through regression analysis, mean square error, and histograms.
Article
Computer Science, Information Systems
Manikandan Rajagopal, Ramkumar Sivasakthivel, Jeyakrishnan Venugopal, Ioannis E. Sarris, Karuppusamy Loganathan
Summary: This research proposes an Extended Lifespan and QSSM-ML routing algorithm to minimize energy depletion in Mobile Adhoc Networks (MANETs) and enhance network lifetime. An optimization problem is formulated to increase network lifespan while limiting energy utilization and stability of the path along with residual. An adaptive policy is applied for asymmetric energy distribution. The algorithm achieves better network performance compared to classical algorithms, as shown in simulation results.
Article
Mathematics, Interdisciplinary Applications
Thomas Zisis, Konstantinos Vasilopoulos, Ioannis Sarris
Summary: This study investigates the impact of different passenger types (elders, travelers with luggage, travelers without luggage, and mixed population) on the evacuation process in railway tunnels after a fire accident using Fractional Effective Dose (FED) index values. The scenario considered is a 20 MW diesel pool fire inside a straight, rectangular railroad tunnel with a longitudinal jet fan ventilation system. Two fire scenarios (with and without ventilation) and four evacuation scenarios were examined. Numerical simulations of the fire and evacuation process were conducted using the Fire Dynamics Simulator and Evacuation code (FDS + Evac), a Large Eddy Simulator (LES) for low-Mach thermally driven flows. The results (evacuation times, walking speeds, and mean and max FED values) were compared for each passenger type. It was found that the elderly are the most affected during evacuation from a railway tunnel fire accident due to their slower movement speed, and travelers with luggage are also significantly affected due to their increased dimensions. Additionally, a non-homogenous population experiences higher uptake of combustion products and longer evacuation times compared to a homogenous population with similar geometrical characteristics.
Article
Mathematics, Interdisciplinary Applications
Georgios R. K. Aretis, Apostolos A. Gkountas, Dimitrios G. Koubogiannis, Ioannis E. Sarris
Summary: Waste heat recovery is a main practice for reducing carbon footprint in the industrial sector. The supercritical carbon dioxide (s-CO2) cycle is an attractive heat-to-power technology due to its high cycle efficiency. This study presents a methodology for the preliminary design of a centrifugal compressor and investigates the three-dimensional flow phenomena and possible condensation occurring in it.
Article
Materials Science, Multidisciplinary
N. Yalini Devi, A. S. Alagar Nedunchezhian, D. Sidharth, P. Rajasekaran, M. Arivanandhan, I. Sarris, T-Y. Yang, R. Jayavel
Summary: Ag and Ag & Nb co-substituted SrTiO3 were synthesized and their structural, morphological and thermoelectric properties were investigated. XRD analysis was used to study the crystal structure and crystallinity. The morphology was analyzed using FESEM and TEM analysis. XPS analysis revealed the presence of Ag and the binding state of each element. The electrical resistivity of Ag-substituted SrTiO3 and the Seebeck coefficient of Ag & Nb co-substituted SrTiO3 were increased with Ag content, leading to improved power factor.
MATERIALS CHEMISTRY AND PHYSICS
(2023)
Article
Mechanics
Nickolas D. Polychronopoulos, Ioannis E. Sarris, Lefteris Benos, John Vlachopoulos
Summary: This study focuses on the rheological behavior of 3D concrete printing (3DCP) and develops approximate expressions for calculating the pressure based on the Bingham model. The predictions are compared to numerical simulations and analytical solutions, showing good agreement within a certain range.
Article
Environmental Sciences
Javali Kotresh Madhukesh, Vinutha Kalleshachar, Chandan Kumar, Umair Khan, Kallur Venkat Nagaraja, Ioannis E. Sarris, El-Sayed M. Sherif, Ahmed M. Hassan, Jasgurpreet Singh Chohan
Summary: Wastewater discharge is crucial in environmental management and industries to conserve water resources and adhere to environmental standards. This study analyzes the impact of pollutant discharge concentration using non-Newtonian nanoliquids over a permeable surface with thermal radiation. Two types of nanoliquids, second-grade and Walter's liquid B, are considered. The governing equations are obtained using boundary layer techniques and reduced to ordinary differential equations using similarity variables. The solutions are obtained using numerical techniques and the effects of dimensionless constraints are illustrated graphically. A comparative analysis between the two nanoliquids is presented, showing that velocity profiles decrease with the porous factor and thermal and concentration profiles are affected by radiation and pollutant source variation. The study also analyzes important engineering factors. The findings will aid in decision-making and planning to reduce pollution and protect the environment.
Article
Thermodynamics
Latifah Falah Alharbi, Anuar Ishak, Umair Khan, Ioannis E. Sarris, El-Sayed M. Sherif, Aurang Zaib, Ahmed M. Hassan
Summary: This study investigates the heat transfer improvement of Williamson hybrid nanoparticles on a shrinking and stretching porous surface. Two different solutions are discovered with the change of influential parameters, and the stability of these solutions is analyzed. Furthermore, the effects of nanoparticle volume fraction on friction factor and heat transfer rate are examined. The results are compared with previous findings to demonstrate the accuracy of the existing technique.
CASE STUDIES IN THERMAL ENGINEERING
(2023)
Article
Materials Science, Multidisciplinary
Mohammad Reza Hajmohammadi, Javad Najafiyan, Giulio Lorenzini
Summary: This study compares three computational approaches for optimizing a thermal conduction problem. The results show that the methods yield similar results in terms of maximum temperature, but the Direct Method (DM) is the fastest when the number of optimization variables is low, while the Pattern Search (PS) technique becomes faster than the Genetic Algorithm (GA) as the number of variables for optimization increases.
FDMP-FLUID DYNAMICS & MATERIALS PROCESSING
(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)
