Article
Thermodynamics
Songzhen Tang, Liang Ding, Ranran Sheng, Kai Zhao, Dongwei Zhang, Bo Shen
Summary: This paper presents a numerical investigation on the heat transfer and flow resistance characteristics of a variable-direction twisted-oval tube (VDTOT). The study analyzes the effects of different geometric parameters on the heat transfer coefficient, pressure drop, and heat transfer capacity. The results show that VDTOT achieves synergistic enhancement of flow and heat transfer performance, thereby increasing the heat transfer capacity compared to circular tubes.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
Hongyi Zou, Lijun Yang, Zhiyuan Huang, Yuan Dong, Ruo-Yu Dong
Summary: In this study, the thermal and mechanical properties of two-dimensional ice (2D ice) were systematically studied using molecular dynamics simulations. The results showed that the thermal conductivity of 2D ice depends on its length and can be increased by decreasing temperature or applying mechanical strains. Additionally, 2D ice exhibited a very low friction and the friction coefficient decreased with decreasing temperature or increasing normal load.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Shengjie Gu, Leren Tao, Cheng Jin, Yiwei Ju, Xiefei Zhao
Summary: This study clarifies the heat transfer characteristics of flow boiling in a narrow vertical rectangular channel and proposes a corresponding heat transfer correlation equation. The results show that an increase in inlet temperature has a positive effect on the nucleate boiling section, while an increase in mass flux has a negative effect on the nuclear state boiling stage. Furthermore, the peak of the local heat transfer coefficient tends to shift to the left as the heating power increases.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Ying-Chieh Hung, Shao-Wei Su, Jia-Wei Yan, Gui-Bing Hong
Summary: In this study, VLE data for five binary systems were measured and successfully correlated using models. The predictive models were used to predict the binary VLE phase diagram and explain the mechanism of separation efficiency. The strength of electrostatic interactions and temperature-dependent separation behavior were determined through the analysis of molecular surface charge distribution.
FLUID PHASE EQUILIBRIA
(2024)
Article
Thermodynamics
Junhong Hao, Tengyu Ma, Jinglong Zhou, Huimin Wei, Yanqiang Kong, Xiaoze Du
Summary: This paper focuses on optimizing the design of proton exchange membrane fuel cells (PEMFCs). A three-dimensional mathematical model of PEMFC is established and simulation data under different structural parameters are collected. By analyzing the simulation data, a mapping relationship between the thickness of the diffusion layer and the output power is derived using response surface analysis. The optimal structural parameters are obtained through the BP neural network. The results show that the fuel cell using a gradient diffusion layer has improved performance compared to using a conventional diffusion layer, including increased average power, overall heat transfer capacity, and oxygen utilization. Furthermore, the paper finds that the fuel cell with a tapered diffusion layer has better synergistic performance in temperature and concentration fields, as well as temperature and velocity fields.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Guillaume Lambou Ymeli, Yan-Yan Feng, Cun-Hai Wang
Summary: This study focuses on the transient radiative transport in irregular geometries of inhomogeneous semitransparent graded-index media. The lattice Boltzmann method and finite volume method are utilized to accurately solve the radiative transfer and analyze its parameters in irregular domains.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
Zhiming Xu, Xiangdong Zhou, Yunfeng Qiu, Jie Xu, Debin Shan, Bin Guo
Summary: In this study, N-doped carbon nanocoatings were prepared on Cu oxide cones by assembly and subsequent pyrolysis of polydopamine. The modified Cu substrate with NC coated Cu oxides showed significantly enhanced boiling heat transfer performance. The vertically-oriented in-plane heat dissipation direction, abundant nucleation sites, and superhydrophilicity of the NC coating synergistically improved the boiling performance.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Rukun Hu, Xinyu Huang, Xinyu Gao, Liu Lu, Xiaohu Yang, Bengt Sund
Summary: This study examines the impact of applying bottom cross-cut on PCM's spatial distribution in a horizontal LHTES unit using numerical simulation. The findings show that bottom cross-cut can improve the heat storage rate and natural convection heat transfer gain.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
Weikang Li, Wenting Zhang, Xiaoyu Huang, Xing Mu, Yuxiang Ni
Summary: Nanophononic materials have the potential to achieve low thermal conductivity through the phenomenon of phonon resonance. In this study, silicon nanofilms with resonant pillars were investigated, and it was found that the thermal conductivity reduction depends on the thickness of the nanofilms and the geometry of the pillars. Additionally, void defects on the pillars were identified to increase the thermal conductivity.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Yuanqing Wu, Shuyu Sun
Summary: The sparse-grid guided PINN training method improves the accuracy of the PINN surrogate model by rearranging collocation points and reduces the training time complexity. Experimental results demonstrate its clear advantages in terms of convergence, stability, and accuracy.
FLUID PHASE EQUILIBRIA
(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
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
Weixin Zhang, Yehang Xie, Yuqiang Ding, Zhao Liu, Zhenping Feng
Summary: This study investigated the impact of upstream slot leakage on the endwall film cooling characteristics of turbine blades. Pressure Sensitive Paint (PSP) technology was used to measure the film cooling characteristics, and numerical analysis was conducted to evaluate the aerodynamic performance. It was found that increasing the mass flow ratio of the upstream slot enhanced film cooling, decreased aerodynamic losses, and reduced the strength of passage vortex. However, reducing the distance between the slot and the blade leading edge only enhanced film cooling without affecting the leakage coverage area.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
Shubham P. Chitriv, Ketaki Dharmadhikari, A. Nithin, Akshay S. Archak, R. P. Vijayakumar, Glen Cletus Dsouza
Summary: This study synthesized PCM composites with UMCNOs and PEG through melt mixing method, and investigated the effects of UMCNOs loading on their properties. The results showed that the addition of UMCNOs can significantly enhance the thermal conductivity and thermal energy storage and release rates of the PCM composites, with negligible impact on phase change properties. This suggests great prospects for latent heat energy storage applications.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Emrehan Guersoy, Hayati Kadir Pazarlioglu, Mehmet Guerdal, Engin Gedik, Kamil Arslan
Summary: The thermo-hydraulic performance of Al2O3/H2O nanofluid with different nanoparticle shapes flowing in a sudden expansion tube with variable sudden expansion inclination angles and elliptical dimpled fins with different diameters were numerically investigated. The results showed that the nanoparticle shapes, sudden expansion inclination angles, and elliptical dimpled fin have significant impact on the thermo-hydraulic performance. This study reveals the novelty and importance of these factors in the research.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
Assia Arab, Nabil Himrane, Zouhira Hireche, Yacine Halouane, Rachid Bennacer, Djamel Eddine Ameziani
Summary: This study investigates the effect of reactive porous separation on ventilation and depollution capacity. The results show that adding reaction improves indoor air quality and reduces air renewal time, without affecting thermal efficiency.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
Chao Zhang, Lijun Li, Shaojie Hu, Lingyun Gou, Renpeng Chen
Summary: In this study, a rigorous thermodynamic formulation is derived to define the concept of adsorption heat and identify its physical sources. The derived adsorption heat expression is formulated as a function of the distance to adsorbent surfaces, facilitating the establishment of a two-parameter sorption isotherm equation.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Vishwanath Ganesan, Raj Patel, Jason Hartwig, Issam Mudawar
Summary: This study consolidates the largest total pressure drop database for cryogenic saturated two-phase flow so far, using experimental data from world literature dating back to 1964. The accuracy of frictional pressure gradient correlations is assessed, and new dimensionless criteria are developed to study the distinct fluid physics unique to cryogens. A hybrid correlation is then developed for the two distinct data subsets, which performs the best among all seminal correlations and provides excellent predictive agreement with the database.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Yanjin Wang, Jintao Xiong, Lingyu Chen, Zhihai Lv, Qian Wang
Summary: A solar radiation transfer model for spray cooling double skin facade (SC-DSF) is proposed in this study. The model is validated by experimental results and various influence factors are analyzed. The effectiveness of adjusting droplet coverage rate and size is also evaluated.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
