Article
Thermodynamics
Darya S. Loenko, Aroon Shenoy, Mikhail A. Sheremet
Summary: This paper presents the computational analysis of unsteady natural convection of a non-Newtonian fluid in an enclosure, considering the time sinusoidal dependence of the wall temperature. The results show the impact of fluid properties and wall temperature oscillation frequency on convective heat and mass transfer.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2021)
Article
Multidisciplinary Sciences
Z. Z. Rashed
Summary: This paper examines the control of three-dimensional dusty nanofluid flow using two circular cylinders with different thermal conditions. The results indicate that the flow can be well controlled using the inner isothermal cylinders, and the cases of heterogeneity in X-Y and X-Z directions lead to lower values of Nu(av). Both the flow and heat transfer rate are enhanced as the distance between the cylinders (delta) is increased.
SCIENTIFIC REPORTS
(2022)
Article
Chemistry, Physical
Zhen Tian, Zhibo Tang, Cong Qi, Lanqi Chen, Yuwei Wang
Summary: In this study, the heat transfer properties of nanofluid in a novel cavity were experimentally investigated. The results showed that the best heat transfer performance was achieved when the amplitude was 3mm and the wave number was 2. This provides important guidance for the design of cavities in the field of photothermal conversion and cooling of electronic components.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2022)
Article
Thermodynamics
Jacob Koshy Mulamootil, Subhasisa Rath, Sukanta Kumar Dash
Summary: The study investigated the importance of temperature-dependent properties combined with the power-law behavior of non-Newtonian fluids around curved surfaces. Significant temperature dependencies were found for the thermal expansion coefficient and consistency index in the class of fluids studied. The influence of curvature on local shear rate distribution and the use of actual temperature differences in the analysis were highlighted as crucial factors affecting the non-Oberbeck-Boussinesq effects.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2021)
Article
Mechanics
Gholamreza Kefayati, Andrew P. Bassom
Summary: Nanofluids are used in various industries to improve heat transfer, and their modeling and simulation are continuously evolving. This study introduces a lattice Boltzmann method for simulating both Newtonian and non-Newtonian nanofluids, with the potential to incorporate any format of extra tensor directly. The method is suitable for studying non-Newtonian nanofluids and has been validated against benchmark problems involving both types of fluids.
Article
Engineering, Chemical
Zhen Tian, Linfei Yue, Cong Qi, Maoqing Tang
Summary: In this study, a new sinusoidal cavity was developed with metal foams partially filled in the inner surface of the hot and cold wall, and Fe3O4-H2O nanofluids were used as the heat-transfer medium. Natural convection of Fe3O4-H2O nanofluids in partially filled metal foam sinusoidal cavities was investigated by considering various variables. It was found that the Nusselt number initially increased significantly and then gradually decreased as the nanofluid concentration increased from wt% = 0.1% to wt% = 0.5%. The results showed that at Q = 25 W, PPI = 40, wt% = 0.5%, the Nusselt number was relatively large, indicating better heat transfer, which provides certain recommendations for the structure design and working condition selection of electronic components.
TRANSPORT IN POROUS MEDIA
(2023)
Article
Engineering, Mechanical
Salaika Parvin, Nepal Chandra Roy, Litan Kumar Saha, Sadia Siddiqa
Summary: Utilizing nanofluids in heat transfer processes within a domain constrained by a square and a wavy cylinder reveals a correlation between the surface characteristics and convective phenomena. Numerical simulations provide parametric results for streamlines, isotherms, and Nusselt numbers, accurately describing the heat transfer behavior.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART C-JOURNAL OF MECHANICAL ENGINEERING SCIENCE
(2022)
Article
Chemistry, Physical
John Shelton, Nanda K. Saini, Syed M. Hasan
Summary: The present study experiments on the rheological properties of Al2O3-TiO2/MO hybrid nanofluids and finds that the flow behavior of the hybrid nanofluids tends to be more Newtonian compared to conventional nanofluids. The study also observes that the ratio of the hybrid mixture of constituent nanoparticle components affect the rheological characteristics of the nanofluids in an intuitive way.
JOURNAL OF MOLECULAR LIQUIDS
(2023)
Article
Thermodynamics
Mikhail A. Sheremet, Hakan F. Oztop
Summary: The study investigates the impact of complex porous fins on nanofluid flow and heat transfer within a heated/cooled cabinet, revealing that the position and penetration of internal porous block are effective characteristics for enhancing heat transfer. Additionally, the addition of alumina nanoparticles suppresses heat transfer and convective flow.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2021)
Review
Chemistry, Multidisciplinary
Farhan Lafta Rashid, Ahmed Kadhim Hussein, Emad Hasani Malekshah, Aissa Abderrahmane, Kamel Guedri, Obai Younis
Summary: Recent studies have explored various strategies to modify heat-transfer rates in closed cavities, such as adding partitions, fins, or altering forms. Experimental and numerical investigations have shown that fin design can enhance heat transmission and accelerate phase change material melting. Additionally, the optimal wind incidence angle for maximum convective heat loss depends on cavity tilt angle and wind speed.
Article
Biochemistry & Molecular Biology
Khaled Al-Farhany, Barik Al-Muhja, Farhan Ali, Umair Khan, Aurang Zaib, Zehba Raizah, Ahmed M. Galal
Summary: Applying heat to technological devices properly is a significant challenge. This study combines numerical simulations and nanofluids to improve convection effects in a square enclosure, exploring the influences of nanoparticle concentration, Rayleigh number, baffle length, and thermal conductivity ratio.
Article
Thermodynamics
Zhong Huang, Botong Li, Xinhui Si, Chanjuan Yao
Summary: This paper investigates the temperature distribution of power-law liquid food under the combination impacts of thermal radiation and natural convection. Results show that the cylindrical container (i.e., the noodle bowl) has the best heating effect, while the temperature fields of egg yolk and egg white are less affected by the generalized Grashof number. The technique of adjusting the generalized Grashof number and thermal radiation for controlling heat transfer behavior could be applied in food engineering applications.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2021)
Article
Mechanics
Karim Ragui, Rachid Bennacer, Mohammed El Ganaoui
Summary: This study demonstrates the oscillatory characteristics of nanofluids in free convective flow within horizontal concentric annuli, utilizing various models to generate ideal suspended particles and incorporate aggregation mechanisms. The accuracy of the numerical tool is validated through multiple tests, leading to the establishment of a new settling chart for non-settling processes in different sizes of annuli.
Article
Mechanics
Gholamreza Kefayati
Summary: A mesoscopic method based on lattice Boltzmann method is introduced to simulate Newtonian and non-Newtonian nanofluids. The model is improved by considering various parameters, and the code is validated with previous studies. The results show good agreement and demonstrate the effectiveness of the proposed method.
Article
Physics, Multidisciplinary
Abdelraheem M. Aly, Zehba Raizah, Noura Alsedias
Summary: The study numerically simulates the thermosolutal convection of circular rotation of dual circular cylinders inside a combined cavity. The connections among the circular rotation of solid cylinders containing nanofluid plus porous media are modeled by the ISPH method. The findings show that the addition of nanoparticles decreases the nanofluid velocity, while increasing the buoyancy parameter accelerates the nanofluid movements and enhances the mean Nusselt number Nu. The variations of porous levels and Rayleigh numbers also affect the nanofluid flow and thermosolutal convection within the combined cavity.
EUROPEAN PHYSICAL JOURNAL PLUS
(2023)
Article
Computer Science, Interdisciplinary Applications
Jiao Liu, Changsheng Huang, Zhenhua Chai, Baochang Shi
Summary: In this paper, a diffuse-interface lattice Boltzmann method (DI-LBM) is developed for fluid-particle interaction problems. By introducing a smooth function and a modified discrete force term, the proposed method shows better accuracy and efficiency in depicting fluid-particle interactions.
COMPUTERS & FLUIDS
(2022)
Article
Computer Science, Interdisciplinary Applications
Fang Shan, Hongyan Du, Zhenhua Chai, Baochang Shi
Summary: A new LB model was proposed to study the capillary rise phenomena of non-Newtonian power-law fluids, showing efficiency and accuracy in simulating two-phase flow dynamics. Significant influences of gravity, viscosity, contact angle, power-law index, and displaced fluids on the capillary rise process were identified through parametric studies.
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS
(2022)
Article
Mechanics
Xiaolei Yuan, Baochang Shi, Chengjie Zhan, Zhenhua Chai
Summary: In this work, an efficient and accurate lattice Boltzmann (LB) model based on phase-field theory is developed to study multiphase flows involving immiscible incompressible fluids. The model adopts a reduction-consistent physical formulation and constructs proper auxiliary source terms to ensure the correct macroscopic equations. The capability of the LB model is demonstrated through numerical examples, and the results show its reduction-consistent property and physical accuracy.
Article
Engineering, Multidisciplinary
Chengjie Zhan, Zhenhua Chai, Baochang Shi
Summary: This study investigates the Soret and Dufour effects of double-diffusive convection over a rough surface. The research finds that the distribution and compactness of rough elements on the surface influence heat and mass transfer as well as flow structure. The effects of factors such as buoyancy ratio, Soret factor, and Dufour factor are also examined. The findings have important implications for understanding the behavior of double-diffusive convection.
APPLIED MATHEMATICAL MODELLING
(2022)
Article
Mathematics, Applied
Changsheng Huang, Zhenhua Chai, Baochang Shi
Summary: The letter introduces a recursive finite-difference lattice Boltzmann model for the convection-diffusion equation with a source term, derived from the lattice Boltzmann method. The model, involving only one macroscopic variable, shows comparable results to the LB method in numerical experiments and can be more accurate with parameter adjustments.
APPLIED MATHEMATICS LETTERS
(2022)
Article
Mathematics, Applied
Fumei Rong, Qianhuan Li, Baochang Shi, Zhenhua Chai
Summary: In this paper, a lattice Boltzmann (LB) model based on the Cole-Hopf transformation is developed for solving the n-dimensional coupled Burgers’ equations. The Cole-Hopf transformation is used to remove the nonlinearity in the convection term, resulting in a simplified diffusion equation that can be effectively solved using the LB model. The model is able to accurately recover the linear diffusion equation and provides convenient calculations for the variables in the Burgers’ equations, thus making it applicable for any n-dimensional coupled Burgers’ equations.
COMPUTERS & MATHEMATICS WITH APPLICATIONS
(2023)
Article
Mathematics, Applied
Xiaolei Yuan, Yao Wu, Chunhua Zhang, Zhenhua Chai, Baochang Shi
Summary: In this work, we propose a unified framework of phase-field-based multiple-relaxation-time lattice Boltzmann (MRT-LB) method for incompressible multiphase flows with density and viscosity contrasts. The framework includes the classic MRT-LB model and central-moments-based LB model (CLBM). The governing equations of incompressible multiphase flows can be accurately reproduced through direct Taylor expansion method at the second-order of expansion parameters. The present model shows better numerical stability and accuracy compared to the traditional Bhatnagar-Gross-Krook (BGK) model, and is capable of simulating multiphase flow problems with large density ratio (1000).
COMPUTERS & MATHEMATICS WITH APPLICATIONS
(2023)
Article
Physics, Fluids & Plasmas
Ying Chen, Zhenhua Chai, Baochang Shi
Summary: In this paper, a fourth-order multiple-relaxation-time lattice Boltzmann (MRT-LB) model is developed for the one-dimensional convection-diffusion equation (CDE) with constant velocity and diffusion coefficient, using the D1Q3 lattice structure. The Chapman-Enskog analysis is performed to recover the CDE from the MRT-LB model. An explicit four-level finite-difference (FLFD) scheme is derived from the MRT-LB model for the CDE, and the truncation error of the FLFD scheme is obtained through Taylor expansion, showing fourth-order accuracy in space at the diffusive scaling. Stability analysis is presented, and the same stability condition is derived for the MRT-LB model and FLFD scheme. Numerical experiments are conducted to test the MRT-LB model and FLFD scheme, which demonstrate a fourth-order convergence rate in space, consistent with the theoretical analysis.
Article
Physics, Fluids & Plasmas
Xi Liu, Zhenhua Chai, Baochang Shi
Summary: In this work, an improved phase-field based lattice Boltzmann method is developed to suppress numerical dispersion and eliminate coarsening phenomenon by using a hybrid Allen-Cahn equation with a flexible weight. Two LB models are adopted to solve the hybrid ACE and the Navier-Stokes equations. The present LB method is validated by five tests and shows superior performance in reducing numerical dispersion and coarsening phenomenon.
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
Physics, Fluids & Plasmas
Zhenhua Chai, Xiaolei Yuan, Baochang Shi
Summary: In this paper, a general rectangular multiple-relaxation-time lattice Boltzmann (RMRT-LB) method is developed for solving the Navier-Stokes equations (NSEs) and nonlinear convection-diffusion equation (NCDE). The method utilizes an equilibrium distribution function (EDF) on a rectangular lattice and extends the relaxation matrix to eliminate the inconsistency caused by lattice anisotropy. Numerical simulations show that the RMRT-LB method is accurate and numerically stable.
Proceedings Paper
Computer Science, Artificial Intelligence
Huanyu Wang, Junjie Liu, Xin Ma, Yang Yong, Zhenhua Chai, Jianxin Wu
Summary: In this paper, a new framework named Mimicking then Replacing (MiR) is proposed for few-sample compression. The framework first requires the pruned model to output the same features as the teacher's in the penultimate layer, and then replaces the teacher's layers before penultimate with a well-tuned compact one. Unlike previous methods, MiR optimizes the entire network holistically, is simple and effective, and is unsupervised and general. MiR outperforms previous methods significantly.
2022 IEEE/CVF CONFERENCE ON COMPUTER VISION AND PATTERN RECOGNITION (CVPR 2022)
(2022)
Article
Physics, Fluids & Plasmas
Zhenhua Chai, Baochang Shi, Chengjie Zhan
Summary: In this paper, a multiple-distribution-function lattice Boltzmann method is proposed for solving the incompressible Navier-Stokes equations. It is shown that the method can recover the Navier-Stokes equations correctly and calculate the velocity and pressure directly using the moments of the distribution function. A locally computational scheme is also developed for calculating velocity gradients and other related physical quantities.
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)
