Article
Construction & Building Technology
Ting Dai, Sumei Liu, Junjie Liu, Nan Jiang, Qingyan Chen
Summary: This study proposes a new dynamic Smagorinsky model for Fast Fluid Dynamics (FFD) which uses an artificial neural network (ANN) to calculate the subgrid stress difference and strain rate tensor difference. The new model significantly reduces the computing time while maintaining similar accuracy, making it a recommended choice for outdoor airflow and pollutant dispersion studies using FFD.
BUILDING AND ENVIRONMENT
(2023)
Article
Thermodynamics
Amir Mardani, Aslan Nazari
Summary: The Eddy Dissipation Concept (EDC) combustion model has gained attention for Moderate or Intense low oxygen Dilution (MILD) combustion. The study investigates the effect of characteristic frequency on the EDC model and performs parametric studies on the ratios of length and time scales. Results show the complexity of finding optimum model constants for different combustion conditions. A localized modulation method based on local variables is developed and applied on various burners, showing improved performance in burner simulation.
COMBUSTION AND FLAME
(2022)
Article
Energy & Fuels
Ivar S. Ertesvag
Summary: Recent proposals to modify or extend the Eddy Dissipation Concept were investigated and compared to the standard EDC. Four different variants of the extended EDC were examined, showing locally determined values for two model coefficients. The constraints on the locally determined coefficients were found to be more significant than the formulated dependencies of turbulence Reynolds number and microscale Damkohler number.
Article
Polymer Science
Xuanyu Zhang, Xiaobin Dai, Wenjie Wei, Wenlong Chen, Lijuan Gao, Li-Tang Yan
Summary: This study investigates the rotational diffusion dynamics and physical mechanism of rod-like particles in macromolecular networks. By conducting large-scale simulations and theoretical analysis, the researchers identify three characteristic rotational dynamics - Brownian, hopping, and restricted, and establish a phase diagram for these rotational patterns based on the diameter and length of the rods. Furthermore, they discover a strong dynamic correlation between rotational and translational dynamics at the boundary between hopping and restricted rotational dynamics. An analytical model is developed to interpret the emergence of hopping rotational dynamics. These findings contribute to the understanding of the fundamental physics of anisotropic particles in confined mediates like macromolecular networks.
Article
Engineering, Environmental
Yu-Heng Deng, Jemin Jeon, Eun Mi Kim, Shengzhe Ding, Sang Ah Lee, Changseon Ryu, Young Jun Kim, Xiao Su, Hyunjoon Kong
Summary: Immobilization of 8-MnO2 nanosheets on a porous support enhances the degradation rate of BPA, with the ability to be recycled and non-toxic to ecological systems. This technology can be extended to remove various water contaminants. Rating: 8/10.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Engineering, Environmental
Mbongiseni Lungelo Dlamini, Mahadi Lesaoana, Izak Kotze, Heidi Richards
Summary: This study investigated a one-pot synthesis procedure of zeolitic imidazolate frameworks (ZIF) and laccase immobilization for the biodegradation of an endocrine-disrupting chemical (EDC), dimethyl phthalate (DMP). The immobilized laccase showed enhanced stability and higher efficiency in DMP removal compared to free laccase. After multiple cycles of reuse, the immobilized lacccase retained high efficiency and improved effectiveness in DMP decontamination from river water samples.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2023)
Article
Thermodynamics
Xu Wen, Louis Dressler, Andreas Dreizler, Amsini Sadiki, Johannes Janicka, Christian Hasse
Summary: Large-eddy simulations were conducted for turbulent methane-hydrogen flames with different modeling approaches, showing varied predictions of flame properties in different regions. The performance of the flamelet models was explored by analyzing the differential diffusion parameter.
COMBUSTION AND FLAME
(2021)
Article
Engineering, Multidisciplinary
M. Safarzadeh, G. Heidarinejad, H. Pasdarshahri
Summary: In this study, the effect of the combustion and turbulence SGS model on simulation of a pool fire turbulence field using OpenFOAM software was investigated. The results showed that the combustion model had a more significant impact on the results, with the EDM model being more compatible with the one-equation SGS model.
Article
Chemistry, Physical
Reo Kai, Taiki Tokuoka, Jun Nagao, Abhishek Lakshman Pillai, Ryoichi Kurose
Summary: The flamelet-generated manifold (FGM) method, which considers preferential diffusion, is applied for large-eddy simulations (LESs) of a lean-premixed H2/air low-swirl lifted flame, and its validity is confirmed through comparison with experimental results. The one-dimensional simulations demonstrate the importance of considering preferential diffusion for accurate prediction of species concentrations near the flame front, which is accurately predicted by the FGM-PD method. Three-dimensional LES results show improved prediction accuracy of velocities near the flame front by employing the FGM-PD method. Additionally, the distribution of OH mass fraction is predicted.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Engineering, Marine
Zhanyang Chen, Weidong Zhao, Xiyu Liao, Mengchao Du
Summary: This paper investigates the equivalent dynamic coefficients (EDC) of a trimaran, particularly focusing on the EDC of the longitudinal girders and transverse frame. By considering the influence of material nonlinearity and transverse bending moment, it is concluded that using EDC to analyze trimarans under slamming loads is feasible.
SHIPS AND OFFSHORE STRUCTURES
(2023)
Article
Physics, Fluids & Plasmas
Shreyas Gokhale, Junang Li, Alexandre Solon, Jeff Gore, Nikta Fakhri
Summary: A dynamic clustering phase is observed in mixtures of colloids and motile bacteria, where colloidal clustering is a result of the balance between bond breaking caused by persistent active motion and bond stabilization caused by torques that align active particle velocity tangentially to the passive particle surface.
Review
Pharmacology & Pharmacy
Akhgar Ghassabian, Laura Vandenberg, Kurunthachalam Kannan, Leonardo Trasande
Summary: This article discusses the unique vulnerability of children to endocrine-disrupting chemicals (EDCs) and the programming effects of EDCs on neuronal, metabolic, immune, endocrine, reproductive, and renal systems. By dispelling myths and providing a list of actions to reduce exposure and harm, it aims to address the health effects of EDCs on child health.
ANNUAL REVIEW OF PHARMACOLOGY AND TOXICOLOGY
(2022)
Article
Chemistry, Multidisciplinary
Sheetal Kumar Jain, Chung-Jui Yu, Christopher Blake Wilson, Tarnuma Tabassum, Danna E. Freedman, Songi Han
Summary: This study extends the application of dynamic nuclear polarization technology by introducing endogenous metal centers for nuclear magnetic resonance enhancement. By tracing polarization transfer, the research deepens understanding of polarization pathways and expands the catalog of polarizing agents.
Article
Polymer Science
Yunfeng Hu, Maciej Podgorski, Sudheendran Mavila, Jasmine Sinha, Benjamin D. Fairbanks, Robert R. McLeod, Christopher N. Bowman
Summary: Dynamic covalent chemistry was employed to improve the holographic grating performance by facilitating diffusion of monomers and network rearrangement in a holographic photopolymer system. The radical-mediated addition-fragmentation chain transfer reaction between allyl sulfide (AS) moieties and thiols provided high spatiotemporal control, making it well-suited for high-quality holographic photopolymers. The exchange with a monofunctional thiol resulted in a significant decrease in molecular weight and viscosity, improving the recording formulations with limited diffusion of monomer and demonstrating a notable improvement of the refractive index modulation.
Article
Toxicology
Rachael E. Rogers, Shuyi Chai, Andrew J. Pask, Deidre M. Mattiske
Summary: Over the past 50 years, significant decreases in fertility have been observed, with female conception rates dropping by 44% and male sperm counts decreasing by over 50%. This decrease can be attributed to increasing exposure to endocrine disrupting chemicals (EDCs), such as Diethylstilbestrol (DES). Women exposed to DES in utero experienced higher rates of infertility, pregnancy complications, and reproductive cancers, with evidence suggesting these effects may persist in future generations.
TOXICOLOGICAL SCIENCES
(2023)
Article
Engineering, Multidisciplinary
Tarek Beji
Summary: This article discusses theoretical work on liquid heat-up in the case of a pool fire, focusing on analyzing convective currents induced by instabilities, estimating the upper layer depth, and proposing improvements for ensuring uniform mixing and calculating the 'effective' thermal conductivity. A novel methodology for the calculation of the 'effective' thermal conductivity is also developed.
JOURNAL OF FIRE SCIENCES
(2021)
Article
Engineering, Civil
Tarek Beji, Olivier Helson, Thomas Rogaume, Jocelyn Luche
Summary: This paper presents experimental tests in a Controlled Atmosphere Cone Calorimeter to study the evaporation rate of n-heptane and methanol. The results show that the evaporation rate of n-heptane increases with time, while methanol reaches a quasi-steady-state. Numerical simulations highlight the importance of accounting for increased heat transfer due to convective motion of the liquid.
FIRE SAFETY JOURNAL
(2021)
Article
Engineering, Civil
Junyi Li, Hugues Pretrel, Tarek Beji, Bart Merci
Summary: The research investigates the influence of fire heat release rate (HRR) evolution on fire-induced pressure variation in contemporary buildings' air-tight compartments. It demonstrates that higher fire growth/decay rate coefficient and maximum steady state HRR result in increased over-pressure/under-pressure peaks, with different timings for pressure peak values based on the fire growth/decay exponent. Additionally, low-frequency oscillatory behavior of gaseous fuel is observed during well-ventilated phases in one test.
FIRE SAFETY JOURNAL
(2021)
Article
Engineering, Civil
Georgios Maragkos, Davood Zeinali, Bart Merci
Summary: Different methods for calculating convective heat fluxes in upward flame spread scenarios were explored, with the approach considering sgs effects performing better in predicting initial flame growth and decay phases. Accurate convective heat transfer modeling was shown to be important in flame spread scenarios.
FIRE SAFETY JOURNAL
(2021)
Article
Computer Science, Interdisciplinary Applications
G. Maragkos, S. Verma, A. Trouve, B. Merci
Summary: This study investigates the impact of numerical schemes on the discretization of convective terms in momentum equations and scalar transport equations. The findings reveal that the native schemes of OpenFOAM, filteredLinear2 and limitedLinear, are relatively accurate compared to other schemes in literature, introducing only small amounts of numerical dissipation while maintaining solution boundedness.
COMPUTERS & FLUIDS
(2022)
Article
Engineering, Civil
Yuanjun Liu, Tarek Beji, Martin Thielens, Zhi Tang, Zheng Fang, Bart Merci
Summary: This paper presents a comprehensive numerical simulation study on a water mist spray from a nozzle positioned 2.2 m from the ground at a pressure of 1.0 MPa. The study reveals the significant impact of drag force modeling on the simulation results, and suggests that reducing the drag coefficient can improve the accuracy of the simulation for dense sprays. The study calls for further development of droplet aerodynamic modeling for dense sprays.
FIRE SAFETY JOURNAL
(2022)
Article
Engineering, Civil
Bouaza Lafdal, Racha Djebbar, Pascal Boulet, Rabah Mehaddi, ElMehdi Koutaiba, Tarek Beji, Jose Luis Torero
Summary: Numerical simulations were conducted to investigate the compartment fire problem with a single door opening. Three combustion regimes were identified based on the average temperature variation inside the compartment, and a linear correlation was found between the maximum heat release rate and the ventilation factor.
FIRE SAFETY JOURNAL
(2022)
Article
Thermodynamics
Bart Merci, Junyi Li, Georgios Maragkos
Summary: A fire in a compartment with limited ventilation can cause significant pressure rise, which is important for both fire safety and understanding fire dynamics. Accurate measurement of heat release rate is crucial, and numerical simulations play a valuable role in studying these phenomena.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Engineering, Multidisciplinary
Tarek Beji
Summary: The paper presents a simplified engineering model for predicting the rate of heat absorption by water droplets interacting with fire-induced smoke. The model uses a decoupled time scale analysis to determine the heat absorbed by droplets during their residence time in the smoke layer. The evaluation results show that the model predicts the absorption rate accurately under certain conditions, but larger deviations are observed under other conditions.
Review
Thermodynamics
Xiepeng Sun, Fei Tang, Kaihua Lu, Fei Ren, Congling Shi, Bart Merci, Longhua Hu
Summary: This paper provides a comprehensive review of recent progresses in the study of window-ejected fire plumes and focuses on quantifying the behavior of these plumes under constrained conditions. The paper discusses the evolution of compartment fires, flame interaction and merging behavior, and characteristic parameters of window-ejected fire plumes. The limitations of current research and future challenges are also addressed.
PROGRESS IN ENERGY AND COMBUSTION SCIENCE
(2023)
Article
Thermodynamics
Shahrooz Motaghian, Tarek Beji
Summary: This paper proposes a new Laminar Smoke Point (LSP)-based soot model that incorporates soot surface growth mechanism. The model has been calibrated and evaluated against a variety of laminar flames, showing better agreement under a wider range of conditions.
COMBUSTION THEORY AND MODELLING
(2023)
Article
Engineering, Civil
Tarek Beji, Bouaza Lafdal, Rabah Mehaddi
Summary: The paper presents experimental measurements of transient profiles of burning rates and liquid temperatures in methanol and heptane pool fires. The results suggest significant enhancement in heat transfer due to convective motion within the liquid. Additionally, a two-zone approach for the thermal structure within the liquid has been proposed and will be implemented in a numerical code.
FIRE SAFETY JOURNAL
(2024)
Article
Engineering, Civil
T. Beji, H. Pretrel
Summary: This paper presents a numerical study on the interaction between two water sprays and smoke generated by a fire in a confined and mechanically-ventilated enclosure. The study finds that the CFD simulations can accurately predict room pressure and overall thermal behavior, but there are some limitations in predicting the thermal stratification loss caused by water spray mixing.
FIRE SAFETY JOURNAL
(2023)
