Thermodynamics

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

Investigation on the solvent and temperature effect of climbazole solubility

Wenxi Song, Na Wang, Mingzhe Tan, Meng Wang, Xin Huang, Ting Wang, Hongxun Hao

Summary: The solubility and thermodynamic behavior of climbazole in different solvents were investigated in this study. The results showed that solubility is influenced by temperature and solvent properties. Furthermore, the solvent effect was evaluated and the molecular mechanism behind the solubility behavior was revealed using solvation energy relationship models and molecular simulation methods.

JOURNAL OF CHEMICAL THERMODYNAMICS (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 Thermodynamics

Thermodynamic consideration of dissolution and distribution behavior of carvedilol in pharmaceutical significant media

Angelica V. Sharapova, Marina V. Ol'khovich, Svetlana V. Blokhina

Summary: This study determined the key physico-chemical properties of cardiovascular carvedilol (CVD) in terms of solubility and distribution coefficients in modeling solvents and biphasic systems. The results showed that the solubility of CVD varied significantly depending on the solvent and pH conditions, and the dissolution process deviated from ideality in saturated solutions.

JOURNAL OF CHEMICAL THERMODYNAMICS (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 Thermodynamics

Influence of the temperature and type of macromolecule on phase diagrams of aqueous two-phase systems

Keycianne da Cruz Silva, Leticia Daniela de Souza, Vinicius Azevedo Gomes, Leandro Rodrigues de Lemos

Summary: Phase diagrams of four aqueous two-phase systems were determined experimentally, and conclusions were drawn regarding the effect of temperature on system enthalpy change and the influence of macromolecules on phase separation.

FLUID PHASE EQUILIBRIA (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

Analysis of agomelatine (Form II) dissolution behavior in different mono-solvents: Solubility, solvation thermodynamics as well as inter-molecular interactions

Jinju Ma, Hao Wu, Dongxu Yi, Wei Liu, Xinding Yao, Tao Li, Baozeng Ren

Summary: In this study, the solubility and compatibility of Agomelatine in different solvents were investigated through experimental and simulation methods. The results showed that Agomelatine forms more stable hydrogen bonds with alcohol solvents compared to other ester solvents. Additionally, the study analyzed the acidity and basicity characteristics of Agomelatine as well as the reasons for differences in solubility.

JOURNAL OF CHEMICAL THERMODYNAMICS (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)

Article Thermodynamics

Two-phase flow and heat transfer on a cylinder via low-velocity jet impact

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

Investigation on natural to ventilated cavitation considering the air-vapor interactions by Merging theory with insight on air jet location/rate effect

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

Effect of fluid-particle interaction on 2D Rayleigh-Benard laminar convection of a temperature-sensitive magnetic fluid

Mufeng Chen, Xiaodong Niu, Peng Yu, Yaping Wang, Adnan Khan, Haruhiko Yamasaki, Hiroshi Yamaguchi

Summary: The Rayleigh-Benard (R-B) laminar convection of a temperature-sensitive magnetic fluid (TSMF) with an immersed nonmagnetic particle in a square cavity heated from the bottom and subject to an external magnetic field is investigated experimentally and numerically. The findings show that the magnetic field slightly affects the onset and transition of convection patterns, and the behavior of the particle depends on its initial location, Ra, and Ram. Additionally, the particle can stabilize the flow and improve heat transfer performance by shifting the higher flow mode to the lower one.

INTERNATIONAL JOURNAL OF THERMAL SCIENCES (2024)

Article Thermodynamics

Natural convection effects in insulation layers of spherical cryogenic storage tanks

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)