Article
Thermodynamics
Tihao Yang, Zelin Wang, Hui Wang, Peixun Yu, Yu Wang
Summary: The heat transfer performance of metal foam is greatly influenced by the flow direction of fluids, with structures having X-direction micropores showing lower pressure drops and higher heat transfer coefficients, while structures having Y-direction micropores displaying higher pressure drops and slightly higher heat transfer coefficients.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2022)
Article
Mathematics, Interdisciplinary Applications
Imran Siddique, Sehrish Ayaz, Fahd Jarad
Summary: This article investigates the unsteady double convection flow of magnetohydrodynamics (MHD) differential-type fluid flow with various heat effects using noninteger-order derivatives. Numerical algorithms are used to solve for concentration, temperature, and velocity fields, revealing that integer-order fluids have higher velocities and studying the impact of fractional parameters on fluid flow.
Article
Thermodynamics
Ke Li, Yuce Liu, Jian Wen, Simin Wang, Jiyuan Tu
Summary: A mass and heat transfer model was proposed to simulate the condensation of binary zeotropic mixtures, and experiments with different mass fluxes and compositions were conducted to validate the model. Results showed good agreement between numerical data and experimental results, and higher R32 content in the mixture led to larger heat transfer coefficients. Mass flux had little effect on R32 vapor concentration.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2022)
Article
Thermodynamics
Olga Arsenyeva, Jiri Jaromir Klemes, Eugeny Klochock, Petro Kapustenko
Summary: This study presents the results of mathematical modelling and experimental study on plate heat exchangers (PHEs) in steam-air mixture condensation. The research shows that the heat transfer area and pressure drop of PHE can vary under different conditions. The optimal corrugation angle and height for plates designed for specific tasks can be selected by solving a future optimization problem with the developed mathematical model.
Article
Biochemical Research Methods
Haibin Li, Gert Desmet, Zhengjin Jiang, Deirdre Cabooter
Summary: Intra-particle diffusion was investigated in particle-packed and monolithic zwitterionic HILIC polymer columns, revealing a very low degree of longitudinal diffusion that may be independent of the zone retention factor. Possible explanations for these low levels of intra-particle diffusion include hindered diffusion in the polymer matrix, extremely low surface diffusion rates in the adsorbed aqueous layer, and slow localized adsorption events.
JOURNAL OF CHROMATOGRAPHY A
(2022)
Article
Engineering, Chemical
Phillip Roche, Roderick C. Jones, Brian Glennon, Philip Donnellan
Summary: A bubble column was used to achieve a desired and controllable rate of evaporation of a pharmaceutical solution, with predicted values proving accurate and errors minimal. The model developed accounted for the effect of reduced vapor pressure caused by dissolved solids, and a method to measure this effect accurately was introduced and applied. The column demonstrated consistent and repeatable evaporation rates, as well as the ability to concentrate solutions effectively in flow, highlighting its reliability in a continuous tandem operation.
Article
Engineering, Environmental
Kun Jiang, Chao Fan, Qiuyang Zhao, Hui Jin
Summary: Using PR-DNS method, this study investigates the gasification process of a single spherical char particle in a high-temperature supercritical CO2/gaseous H2O atmosphere. The effects of reaction temperature and Reynolds number on the drag coefficient, flow field, interphase thermal and mass transfer near the particle surface are analyzed. The results show that higher reaction temperature leads to smaller drag coefficient and improved heat transfer performance. The characteristics of temperature and Reynolds number vary under different reaction temperatures, indicating kinetically-controlled reactions in the gasification process.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Thermodynamics
Junjun Guo, Lingqi Shen, Xiaoyi He, Zhaohui Liu, Hong G. Im
Summary: The study evaluates the weighted sum of gray gases (WSGG) models for turbulent jet diffusion flame simulations, showing that the model based on mixture modeling provides good prediction accuracy with lower computational cost. The combination of mixture modeling with non-gray soot radiative property model offers the best accuracy for gas-soot mixture.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Thermodynamics
Ji-Hwan Hwang, Hyun-Jae Kim, Dong-Wook Jerng
Summary: This study investigates the impact of wall subcooling on condensation heat transfer in a steam-air mixture on a vertical tube. Both experimental analysis and heat and mass transfer model were used to analyze the effect of wall subcooling. The results show that the effect of wall subcooling on condensation heat transfer varies with the degree of subcooling, with a smaller decrement of heat transfer observed at low subcooling. The presence of noncondensable gas fraction also affects the wall subcooling effect. Based on the analysis, an empirical correlation for condensation heat transfer over a wide range of wall subcooling was developed, which predicted the experimental results well, particularly at low subcooling conditions.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2023)
Article
Nanoscience & Nanotechnology
Phong Hoai Le, Yasuhiko Kitamoto, Shunki Yamashita, Kiet Le Anh Cao, Tomoyuki Hirano, Tareq W. M. Amen, Nao Tsunoji, Takashi Ogi
Summary: In recent years, transportation-related air pollution has become a global concern. This study focused on the development of a three-way catalyst (TWC) technology to reduce harmful emissions. The researchers synthesized macroporous TWC particles with different macropore sizes and found that the size of the macropores significantly affected the catalytic performance of the TWC structures. The study proposed a plausible mechanism to explain the influence of macropore size on the diffusion efficiency within the structures.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Engineering, Chemical
Alexander Van-Brunt, Patrick E. Farrell, Charles W. Monroe
Summary: This article presents the Onsager-Stefan-Maxwell thermodiffusion equations, which explain the Soret and Dufour effects in multicomponent fluids. This framework preserves the structure of the isothermal Stefan-Maxwell equations and separates the forces driving diffusion and heat flow. The authors demonstrate the feasibility of this method through numerical simulations.
Article
Engineering, Chemical
Jonas Hedlund, Mojtaba Sinaei Nobandegani, Liang Yu
Summary: The study found that surface barriers in MFI and CHA membranes may be a surface diffusion process with higher activation energy, with other possible mechanisms not ruled out. For pure components at low concentration in MFI zeolite, the barrier is proportional to the product of the molecular weight and heat of desorption; while at high concentration, the barriers of the components become more similar due to interaction effects.
JOURNAL OF MEMBRANE SCIENCE
(2022)
Article
Thermodynamics
Sharmi Mazumder, H. M. M. Afroz, M. A. Hossain, Akio Miyara, Shaon Talukdar
Summary: Research is underway to find a low-GWP alternative to R410A for household HVAC&R systems. The heat transfer characteristics of zeotropic mixtures of R32/R1234ze (E) as replacements for R410A were analyzed, showing that the heat transfer coefficient is influenced by factors such as mass flux, saturation temperature, and initial mixture compositions.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Thermodynamics
Il Woong Park, Si Hyuk Yang, Yeon-Gun Lee
Summary: This study identified the characteristics of condensation heat transfer deterioration due to light gas, discussed parameters affecting the heat transfer coefficient, and observed a gradual deterioration in the heat transfer coefficient with increasing mole fraction of helium. Additionally, conditions for helium stratification during condensation were identified.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Engineering, Chemical
A. Karela, S. M. Clarke, G. Kawaley, A. F. Routh, D. Wilson
Summary: The crystallisation fouling caused by cooling of aqueous solutions of 10-40 wt% tetrabutylammonium bromide (TBAB) and trimethyloethane (TME) was studied. Semi-solid layers of crystals were formed on the heat transfer surfaces. Different hydration states were confirmed, especially for TBAB, which could be reasonably described by simple models. The enthalpy of fusion was measured, and Fickian diffusivities were estimated using DOSY NMR.
CHEMICAL ENGINEERING SCIENCE
(2022)