Article
Thermodynamics
Shugang Wang, Chen Wang, Jihong Wang, Shuang Jiang, Tengfei Zhang, Zhenjun Ma
Summary: This work aims to analytically study the thermal behavior of phase change nano-capsules (PCNCs) during forced convective cooling when its initial temperature is greater than the fusion temperature. Asymptotic solutions are developed for long- and small-time scales using perturbation method with boundary-fixing transformations. The derived solutions are validated with experimental data and show good agreement. The analytical solutions provide a convenient option for engineering applications.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Energy & Fuels
Mojtaba Safdari, Sadegh Sadeghzadeh, Rouhollah Ahmadi, Fatemeh Molaei
Summary: This study focuses on reformulating the generalized differential quadrature method for the Stefan problem in latent heat thermal storage systems. Comparison and convergence demonstrate confidence in the proposed method, with error depending on Stefan number.
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
(2022)
Article
Engineering, Mechanical
Simon Pfeil, Hauke Gravenkamp, Fabian Duvigneau, Elmar Woschke
Summary: A semi-analytical solution of the Reynolds equation is developed based on the scaled boundary finite element method (SBFEM), combining it with a nonlinear cavitation model. The resulting bearing forces are in good agreement with a standard numerical reference solution.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2023)
Article
Chemistry, Analytical
Manzoor Ahmed Hashmani, Mehak Maqbool Memon, Kamran Raza, Syed Hasan Adil, Syed Sajjad Rizvi, Muhammad Umair
Summary: Super-pixels are perceptually similar groups of pixels that are generated based on color and pixel proximity. The existing SLIC method lacks accuracy and efficiency on semi-dark images. We propose a novel SLIC extension, SLIC++, which incorporates a hybrid distance measure to improve accuracy and performance on semi-dark images.
Article
Mathematics
Shuang Luo, Fu-Yao Zhao
Summary: We propose a general method for constructing the semi-analytical solution of the inverse Laplace transform, using the powerful exponential approximation invented by Wang et al. in 1993. This method inherits all the merits such as analytical expression, avoiding free parameters, simple calculation with high accuracy, and the availability of error estimation. Illustrating calculations indicate the potential applications to the vast problems in the fields of mathematical physics as well as engineering and medicine.
JOURNAL OF MATHEMATICS
(2022)
Article
Biochemical Research Methods
Meng-Yu Tsai, Leia Fan, Jessica Tseng, Jason Lin, Andy Tseng, Eric Lee
Summary: This study presents an analytical formula to calculate the motion of droplets with arbitrary surface potentials in a dilute electrolyte solution. Viscosity affects the speed of movement for dielectric droplets, while it has the opposite effect for conducting droplets. The presence of a spinning electric driving force on the droplet surface is responsible for this difference.
Article
Engineering, Civil
Adnan Enajar, Ashraf El Damatty, Ashraf Nassef
Summary: This paper introduces a computationally efficient procedure for analyzing the detachment of roofs of light-frame wood houses during hurricane events. The new model effectively simulates nonlinear analysis of roofs, demonstrating its reliability in considering spatial and temporal variations of wind loads. It can be used for probabilistic analysis of roofs in the future.
ENGINEERING STRUCTURES
(2021)
Article
Mathematics, Applied
Poorya Taghvaei, Hanif Pourshahbaz, Jaan H. Pu, Manish Pandey, Vahid Pourshahbaz, Saeed Abbasi, Nafiseh Tofangdar
Summary: In this paper, the variational iteration method was utilized to obtain a semi-analytical solution for the 1D advection-dispersion equation in temporally dependent solute dispersion within uniform steady flow. The study found that the change in flow velocity has a strong effect on fluid density variation, while the increase in diffusion coefficient has a negligible impact on flow and velocity behaviors.
ZAMM-ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND MECHANIK
(2022)
Article
Materials Science, Multidisciplinary
Zhi-Yong Fan, Khalid K. Ali, M. Maneea, Mustafa Inc, Shao-Wen Yao
Summary: In this work, three different techniques are applied to solve the Fitzhugh-Nagumo equation, which is important for describing the propagation of electrical signals in excitable media. The methods used, including the residual power series method, homotopy perturbation method, and a modified fractional Taylor expansion, provide accurate solutions for nonlinear fractional partial differential equations. The comparison between exact and approximate solutions demonstrates the efficiency and high accuracy of these methods. Various 2D and 3D graphs are shown to support the analysis.
RESULTS IN PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Zhuo-Er Liu, Yujie Wei
Summary: Crack branching is common in engineering practice and analyzing the mechanical properties of branched cracks is important for safety analysis and crack-path engineering. In this work, we developed a theoretical method to calculate the stress intensity factors (SIFs) of branched cracks using Schwarz-Christoffel mapping and Muskhelishvili approach. The convenience and accuracy of this method were demonstrated by obtaining SIFs for forked cracks and four-branched cracks. The theoretical solutions were validated using finite-element simulations and showed good agreement. These analytical methods provide a general way to solve SIFs and the energy release rate of branched cracks, which can be applied to understand crack splitting and crack network engineering.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2023)
Article
Construction & Building Technology
Renato Zona, Paolo Ferla, Vincenzo Minutolo
Summary: The evaluation of limit loads of masonry domes is essential for historical buildings preservation and transformation. The proposed approach in the paper combines analytic and finite element methods to assess the structure's collapse load under actual loads, providing a safety assessment for prescribed load patterns and geometries.
JOURNAL OF BUILDING ENGINEERING
(2021)
Article
Engineering, Mechanical
Kumar Milind Rewanand Shripad, Sriram Sundar
Summary: This article introduces a semi-analytical technique called the harmonic balance method (HBM), based on contact-mechanics-based model, to accurately predict the steady-state response of dynamic systems with clearance nonlinearity and excitation. By comparing and evaluating multiple variants of HBM, the most suitable variant for the system under consideration is selected. A new smoothing function is proposed to handle the discontinuities in the system and improve the accuracy of HBM. The selected variant of HBM is validated against numerical results and used to estimate the nonlinear frequency response of the system with multiple discontinuities, showing good agreement.
NONLINEAR DYNAMICS
(2023)
Article
Geochemistry & Geophysics
He Tang, Wenke Sun, Tai Liu
Summary: Numerous physical processes, including surface water and groundwater conversion, volcanic eruptions, and underground mining, are responsible for mass exchange between the Earth's surface and interior. These mass transport phenomena significantly influence the deformation of the Earth's crust. In this study, we analyze the extent of crustal deformation by obtaining Green's functions due to internal mass loading in a layered elastic spherical earth model. The displacement and gravity change show significant differences between surface source and internal source within a specific horizontal range multiple times the source depth. Horizontal displacement is more sensitive to source depth. Additionally, we have published the code for calculating Green's function for internal mass loading on GitHub.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Engineering, Civil
J. C. Monge, J. L. Mantari, R. A. Arciniega
Summary: This paper investigates the three-dimensional bending solution of doubly-curved shells subjected to mechanical, thermal, and hygrothermal loads. The temperature profile through the shell is modeled using Fourier's heat conduction equation, while the hygro-thermal profile is determined using Fick's moisture diffusion law. The governing equations are solved using Navier closed form summations, and the thickness profile is discretized using Legendre's grid distribution and solved using the Differential Quadrature Method (DQM). Results for cylindrical, spherical panels, and rectangular plates are presented and compared with existing solutions in the literature.
ENGINEERING STRUCTURES
(2022)
Article
Thermodynamics
Jian Dong, Guanghui Hu, Yiping Zhao, Chao Si, Long Jiao
Summary: This paper models the evolution and heat transfer of a single spherical condensate droplet on a superhydrophobic surface and analyzes the inaccuracy of the current method for calculating the heat conduction resistance. A new semi-analytical model is proposed which is more accurate and reduces heat transfer calculation errors, particularly for large droplets and large contact angles.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Mathematics, Applied
Kathrin Eisenschmidt, Moritz Ertl, Hassan Gomaa, Corine Kieffer-Roth, Christian Meister, Philipp Rauschenberger, Martin Reitzle, Karin Schlottke, Bernhard Weigand
APPLIED MATHEMATICS AND COMPUTATION
(2016)
Article
Thermodynamics
Florica Ioana Dragomirescu, Kathrin Eisenschmidt, Christian Rohde, Bernhard Weigand
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2016)
Article
Computer Science, Software Engineering
Grzegorz Karol Karch, Fabian Beck, Moritz Ertl, Christian Meister, Kathrin Schulte, Bernhard Weigand, Thomas Ertl, Filip Sadlo
IEEE TRANSACTIONS ON VISUALIZATION AND COMPUTER GRAPHICS
(2018)
Article
Computer Science, Interdisciplinary Applications
P. Rauschenberger, A. Criscione, K. Eisenschmidt, D. Kintea, S. Jakirlic, Z. Tukovic, I. V. Roisman, B. Weigand, C. Tropea
COMPUTERS & FLUIDS
(2013)
Article
Thermodynamics
B. Weigand, K. Eisenschmidt
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2012)
Proceedings Paper
Computer Science, Artificial Intelligence
Daniel Kloetzl, Tim Krake, Youjia Zhou, Jonathan Stober, Kathrin Schulte, Ingrid Hotz, Bei Wang, Daniel Weiskopf
Summary: This paper presents a new topological connection method for improving the visual representation of the local bi-linear computation of Jacobi sets, while preserving the topological structure and geometric configuration. The method utilizes the topological structure of the local bilinear method and proposes a homotopy-equivalent representation to remove artifacts and reduce clutter.
2022 IEEE WORKSHOP ON TOPOLOGICAL DATA ANALYSIS AND VISUALIZATION (TOPOINVIS 2022)
(2022)
Proceedings Paper
Thermodynamics
Cameron Tropea, Bernhard Weigand, Kathrin Schulte
28TH CONFERENCE ON LIQUID ATOMIZATION AND SPRAY SYSTEMS, ILASS-EUROPE 2017
(2017)
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)