Kenta Hashimoto¹, Guohui Sun¹, Yasushi Koito^2,*

Frontiers in Heat and Mass Transfer, Vol.22, No.3, pp. 687-702, 2024, DOI:10.32604/fhmt.2024.052928

Abstract Centered or striped wick structures have been used to develop ultrathin heat pipes. Differing from traditional heat pipes, the centered or striped wick structures leave noncontact container surfaces with the wick structure. In this study, experiments and numerical analyses were conducted to investigate the influence of these noncontact surfaces. In the experiments, a strip-shaped wick structure was placed vertically, the top was sandwiched between wider rods and the bottom was immersed in a working fluid. The rod width was greater than the wick width; thus, noncontact surfaces were left between the rod and the wick… More >

Abir Abboud¹, Zakaria Triki¹, Rachid Djeffal², Sidi Mohammed El Amine Bekkouche², Hichem Tahraoui^1,3,4, Abdeltif Amrane⁴, Aymen Amin Assadi⁵, Lotfi Khozami⁵, Jie Zhang^6,*

Frontiers in Heat and Mass Transfer, Vol.22, No.3, pp. 769-789, 2024, DOI:10.32604/fhmt.2024.050330

Abstract As buildings evolve to meet the challenges of energy efficiency and indoor comfort, phase change materials (PCM) emerge as a promising solution due to their ability to store and release latent heat. This paper explores the transformative impact of incorporating PCM on the hygrothermal dynamics of multi-zone constructions. The study focuses on analyzing heat transfer, particularly through thermal conduction, in a wall containing PCM. A novel approach was proposed, wherein the studied system (sensitive balance) interacts directly with a latent balance to realistically define the behavior of specific humidity and mass flow rates. In addition, More >

Chunlei Ruan^1,2,*, Cengceng Dong¹, Zeyue Zhang¹, Boyu Chen¹, Zhijun Liu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.140, No.3, pp. 2707-2728, 2024, DOI:10.32604/cmes.2024.050003

Abstract Transient heat conduction problems widely exist in engineering. In previous work on the peridynamic differential operator (PDDO) method for solving such problems, both time and spatial derivatives were discretized using the PDDO method, resulting in increased complexity and programming difficulty. In this work, the forward difference formula, the backward difference formula, and the centered difference formula are used to discretize the time derivative, while the PDDO method is used to discretize the spatial derivative. Three new schemes for solving transient heat conduction equations have been developed, namely, the forward-in-time and PDDO in space (FT-PDDO) scheme,… More >

Kaituo Jiao¹, Dongxu Han^2,*, Bo Yu²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.27, No.4, pp. 1-5, 2023, DOI:10.32604/icces.2023.09168

Abstract Acid fracturing is critical to improving the connectivity inside underground reservoirs, which involves a complex thermal-hydro-mechanical-chemical (THMC) coupling process, especially deep underground. Heat conduction anisotropy is one of the intrinsic properties of rock. It determines the heat response distribution inside the rock and alters the temperature evolution on the reactive surface of fractures and pores. In another way, the rock dissolution rate is closely related to the reactive surface temperature. Predictably, heat conduction anisotropy leads to different rock dissolution morphologies from that of the heat conduction isotropy situation, then the cracks distribution and permeability of… More >

Wenjun Chen¹, Yingjun Wang^1,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.27, No.3, pp. 1-1, 2023, DOI:10.32604/icces.2023.09096

Abstract The rapid development of topology optimization has given birth to a large amount of different topology optimization methods, and each of them can manage a class of corresponding engineering problems. However, structures need to meet a variety of requirements in engineering application, such as lightweight and multiple load-bearing performance. To design composite structures that have multiple structural properties, a new multi-scale topology optimization method considering multiple structural performances is proposed in this paper. Based on the fitting functions of the result set and the bisection method, a new method to determine the weight coefficient is… More >

Iqbal M. Batiha^1,2,*, Iqbal H. Jebril¹, Mohammad Zuriqat³, Hamza S. Kanaan⁴, Shaher Momani^5,*

Frontiers in Heat and Mass Transfer, Vol.21, pp. 487-504, 2023, DOI:10.32604/fhmt.2023.045021

Abstract Several researchers have dealt with the one-dimensional fractional heat conduction equation in the last decades, but as far as we know, no one has investigated such a problem from the perspective of developing suitable fractionalorder methods. This has actually motivated us to address this problem by the way of establishing a proper fractional approach that involves employing a combination of a novel fractional difference formula to approximate the Caputo differentiator of order α coupled with the modified three-point fractional formula to approximate the Caputo differentiator of order 2α, where 0 < α ≤ 1. As More >

Yu Xiang¹, Bao Qin², Zheng Zhong^1,*, Zhenjun Jiao^1,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.26, No.4, pp. 1-1, 2023, DOI:10.32604/icces.2023.09088

Abstract A thermo-chemo-mechanically (TCM) coupled peridynamic (PD) model is proposed to analyze the crack behavior in solids considering heat conduction, species diffusion, and chemical reactions. A PD theoretical framework is established based on non-equilibrium thermodynamics. The influences of species diffusion and chemical reactions on the Helmholtz free energy density and the subsequent formation and propagation of cracks are distinguished by introducing the concentration of diffusive species and the extent of the chemical reaction. Furthermore, inter-physics coupling coefficients are calibrated by equating the corresponding field in the PD model to the continuum mechanics under the same condition. More >

Wenjun Chen¹, Yingjun Wang^1,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.26, No.2, pp. 1-1, 2023, DOI:10.32604/icces.2023.09095

Abstract The rapid development of topology optimization has given birth to a large amount of different topology optimization methods, and each of them can manage a class of corresponding engineering problems. However, structures need to meet a variety of requirements in engineering application, such as lightweight and multiple load-bearing performance. To design composite structures that have multiple structural properties, a new multi-scale topology optimization method considering multiple structural performances is proposed in this paper. Based on the fitting functions of the result set and the bisection method, a new method to determine the weight coefficient is… More >

Mohamed Shaimi^* , Rabha Khatyr, Jaafar Khalid Naciri

Frontiers in Heat and Mass Transfer, Vol.20, pp. 1-14, 2023, DOI:10.5098/hmt.20.23

Abstract This paper presents an exact analytical solution to the extended Graetz problem in microchannels and microtubes, including axial heat conduction, viscous dissipation, and rarefaction effects for an imposed constant wall temperature. The flow in the microchannel or microtube is assumed to be hydrodynamically fully developed. At the same time, the first-order slip-velocity and temperature jump models represent the wall boundary conditions. The energy equation is solved analytically, and the solution is obtained in terms of Kummer functions with expansion constants directly determined from explicit expressions. The local and fully developed Nusselt numbers are calculated in… More >

Salvatore Brischetto^*, Roberto Torre, Domenico Cesare

CMES-Computer Modeling in Engineering & Sciences, Vol.136, No.3, pp. 2551-2594, 2023, DOI:10.32604/cmes.2023.026312

Abstract This new work aims to develop a full coupled thermomechanical method including both the temperature profile and displacements as primary unknowns of the model. This generic full coupled 3D exact shell model permits the thermal stress investigation of laminated isotropic, composite and sandwich structures. Cylindrical and spherical panels, cylinders and plates are analyzed in orthogonal mixed curved reference coordinates. The 3D equilibrium relations and the 3D Fourier heat conduction equation for spherical shells are coupled and they trivially can be simplified in those for plates and cylindrical panels. The exponential matrix methodology is used to… More >