Engineering, Mechanical

Article Thermodynamics

Parametric analysis of different Al2O3 nanoparticle shapes and expansion angles for sudden expanded tube regarding the first law of 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

Analysis of a reactive porous separation effects on depollution and indoor air quality: Application of LBM-MRT to heat and mass transfers

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

Physical origin of adsorption heat and its significance in the isotherm equation

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

Development of Two-Phase Frictional Pressure Gradient Correlation for Saturated Cryogenic Flow Boiling in Uniformly Heated Tubes

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

A study on the model of solar radiation transfer in multi-layer glass facade with attached droplets

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)

Article Thermodynamics

Experimental and numerical investigation on the influence of wall deformations on mixing quality of a Multifunctional Heat Exchanger/Reactor (MHER)

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

Characterization of directional and anisotropic scattering dependency of emissivity for fibrous heat shields under non-isothermal conditions

Ahmed H. Yassin, Savio J. Poovathingal

Summary: In this study, the spectral and directional dependence of emissivity in scattering media were investigated. It was found that emissivity is strongly influenced by the scattering albedo and anisotropic scattering phase function. A generalized relation between spectral emissivity and scattering behavior for thick optical media was established using Bezier curves. A novel model was also developed to capture emissions from a medium with a non-uniform temperature distribution. This new approach provides a practical solution for the radiation energy balance at surfaces in computational fluid dynamics and thermal response simulations.

INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER (2024)

Article Thermodynamics

Ice accretion compositions in ice crystal icing

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

Study on numerical model of thermal conductivity of non-aqueous phase liquids contaminated soils based on mesoscale

Yalu Han, Yanlong Wang, Chenyang Liu, Xinmin Hu, Yin An, Zhengcai Li, Jiaxun Jiang, Lizhi Du

Summary: This paper investigates the calculation method of thermal conductivity in NAPLs-contaminated soils. By establishing NAPLs-contaminated soil models and using the Lattice Boltzmann Method (LBM) for calculation, an optimized three-dimensional model with high computational accuracy and efficiency is obtained. The study also finds that saturation and Nz parameters have a significant impact on calculation time, while the thermal conductivity of the two-dimensional model is more sensitive to anisotropy. The influence of porosity and NAPLs content on thermal conductivity should be considered during in-situ thermal desorption.

INTERNATIONAL JOURNAL OF THERMAL SCIENCES (2024)

Article Thermodynamics

Cooling performance of the hot-rolled seamless steel tube with different jet forms

Rui Zhang, Zhen-lei Li, Yan-sheng Zhang, Dong Chen, Guo Yuan

Summary: This study discusses the heat transfer behavior of different jet forms on steel tubes. The results show that the annular jet performs better in terms of cooling intensity and uniformity. The cooling performances of the two jet forms are similar when the steel tube size is small. Therefore, the planar jet can be considered for smaller diameters due to its simplicity, low cost, and convenience in application.

INTERNATIONAL JOURNAL OF THERMAL SCIENCES (2024)

Article Engineering, Mechanical

Predicting the wear rate of Alumina/MoS2 nanocomposite coating by development of a relation between lancaster coefficient & surface parameters

Mohammad Roostaei, Arvin Taghizadeh Tabrizi, Hossein Aghajani

Summary: In this research, the Al2O3/MoS2 nanocomposite coating layer was successfully applied on the surface of Ti-6Al-4 V alloy. The relation between the surface characteristics and wear resistance of the coating was studied using atomic force microscopy analysis and pin-on-disk wear test method. The results showed that the nanocomposite coating significantly reduced the wear rate and provided an equation to calculate the Lancaster coefficient.

TRIBOLOGY INTERNATIONAL (2024)

Article Engineering, Mechanical

Influence of a transmission oil degradation on physico-chemical properties and tribological performance

Busra Duran, Jerome Cavoret, David Philippon, Fabrice Ville, Arnaud Ruellan, Frank Berens

Summary: This study analyzes the changes in the physicochemical properties and tribological performances of gear transmission oils during field operation, finding differences from traditional engine oils.

TRIBOLOGY INTERNATIONAL (2024)

Article Thermodynamics

A comparative study of purge slot exit shape on the film cooling effectiveness of a gas turbine shroud

Gi Mun Kim, Jin Young Jeong, Young Jun Kang, Jae Su Kwak

Summary: To achieve higher efficiency and performance, it is important to effectively inject purge flow to protect the endwall surface in a gas turbine. The present study investigated the effect of purge slot exit shape on the film cooling effectiveness (FCE) of a shroud surface. The results showed that wider slot width improved FCE, while the fillet radius at the windward side had a negative effect on FCE.

INTERNATIONAL JOURNAL OF THERMAL SCIENCES (2024)

Article Engineering, Mechanical

An experimental investigation on machining-induced surface/subsurface characteristics of nickel based Inc-718 alloy: A novel hybrid approach in milling process

Musa Bilgin, Sener Karabulut, Halil Karakoc, Yunus Kayir, Murat Sarikaya

Summary: This study investigates various methods to improve the machinability efficiency of Inconel 718 alloy while considering their effect on microstructural properties. The results show that hot+PMQL, hot+SiCNMQL, and hot+Al2O3-NMQL contribute significantly to the improvement of machinability characteristics. The EBSD analysis also reveals that a limited area is affected by heat in the hot machining environment and that the removal of the heated layer during milling process helps preserve the microstructure.

TRIBOLOGY INTERNATIONAL (2024)

Article Thermodynamics

Electrically tunable and switchable perfect infrared absorber based on ENZ material

Yunxia Ma, Fei Liu, Honggang Pan, Hongjian Zhang, Shuxia Yan, Ailing Zhang

Summary: This paper proposes a dynamically tunable and switchable perfect infrared absorber that exhibits excellent electrical regulation performance and high absorptance. The absorption mechanism is explained using a multiple interference model, and it is proven to be polarization insensitive.

INTERNATIONAL JOURNAL OF THERMAL SCIENCES (2024)

Article Thermodynamics

Experimental investigation on self-induced jet impingement boiling using R1336mzz(Z)

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

Supercritical heat transfer of CO2 in horizontal tube emphasizing pseudo-boiling and stratification effects

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)

Article Thermodynamics

Numerical evaluation of heat-triggered drug release via thermo-sensitive liposomes: A comparison between image-based vascularized tumor and volume-averaged porous media models

G. Adabbo, A. Andreozzi, M. Iasiello, G. P. Vanoli

Summary: This study compares two numerical models for controlled drug delivery through thermo-sensitive liposomes under mild microwave hyperthermia. The vascular-scale model provides more precise information about temperature field distribution and drug localization within the tumor tissue, while the volume-averaged model presents a more uniform temperature field and drug distribution. The findings suggest using the vascular-scale approach for precision and accuracy, and the volume-averaged approach for average outcomes.

INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER (2024)

Article Thermodynamics

Numerical study on multiphase evolution and molten pool dynamics of underwater wet laser welding in shallow water environment

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

Experimental study of the temperature characteristics of the main cables and slings in suspension bridge fires

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)