Article
Thermodynamics
Diego Alcaniz, Paolo Caccavale, Maria Valeria De Bonis, Ruth de los Reyes, Maria Dolores Ortola, Gianpaolo Ruocco
Summary: A new fluid heater based on BCET was proposed in this paper, with fully-dimensional thermo-fluid analysis implemented to achieve more uniform and effective heat transfer to temperature-sensitive working fluids. Through geometry optimization with internal baffles, the uncontrolled temperature excess was significantly reduced, while the pressure drop across the flow device was also lowered.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2021)
Article
Thermodynamics
Sihao Qian, Shunxi Lou, Chaoliu Ge, Wei Wang, Xiwei Tian, Yanzhao Cai
Summary: This study investigates the influence of temperature dependent fluid properties on the topology optimization of conjugate heat transfer. The coupling between fluid flow and heat transfer caused by non-isothermal flow is demonstrated by introducing functions of material TD properties. The results show that TD fluid properties will cause different topology optimization results and affect heat dissipation capacity, which cannot be neglected in topology optimization studies.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2022)
Article
Computer Science, Interdisciplinary Applications
Nikolaos Galanos, Evangelos M. Papoutsis-Kiachagias, Kyriakos C. Giannakoglou, Yoshiyuki Kondo, Koichi Tanimoto
Summary: This method combines topology and shape optimization for the design of bi-fluid heat exchangers. It takes into account heat transfer between two fluids and a solid material with a continuous porosity field and a penalization term. The method overcomes inaccuracies of the original method by improving interpolation scheme and using a successive implementation of optimization steps.
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2022)
Article
Computer Science, Interdisciplinary Applications
Brice Rogie, Casper Schousboe Andreasen
Summary: This paper demonstrates the advantages of topology optimization of heat sinks, beyond the capabilities of pseudo 3D models. It investigates the use of 3D effects for microchannel heat sinks and compares them to state-of-the-art industrial designs for microelectronic applications. The study shows that the performance of microchannel heat sinks highly depends on complex refrigerant distribution and intricate flow paths, and a 3D topology optimized microchannel heat sink can significantly reduce the temperature elevation of a microelectronic chip.
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2023)
Article
Thermodynamics
Benedetto Mele, Gianpaolo Ruocco
Summary: This paper presents convection/conduction simulations to investigate the flow and heat transfer phenomena in a steady-state plate with embedded discrete heaters, subjected to a turbulent cooling jet. The results show that the configuration and properties of the discrete heaters have a significant influence on the heat transfer performance and temperature distribution.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Thermodynamics
Jan Bohacek, Miroslav Raudensky, Ilya Astrouski, Ebrahim Karimi-Sibaki
Summary: Polymeric hollow-fiber heat exchangers are a viable alternative to metallic plate fin heat exchangers, offering various advantages. By setting up a numerical model and validating with experiments, optimal design parameters were determined to achieve the best performance of the heat exchanger.
Article
Thermodynamics
Olivier Cleynen, Sebastian Engel, Stefan Hoerner, Dominique Thevenin
Summary: This study combines computational fluid dynamics simulation and genetic optimizer to optimize the free-stream water wheel, aiming to maximize hydraulic efficiency and power density.
Article
Thermodynamics
Paul Dillon
Summary: High temperature heat treatment is often used in the manufacturing process of commercial products, which requires a specific temperature-time profile. A novel CFD simulation model is developed for heat transfer in the cooling section of a continuous furnace. This model includes multiple solid domains and uses a dual-solver approach to solve for convective and radiant heat transfer in the gas phase and heat conduction in the solid phases separately. The model provides a snapshot of the thermal performance of the system in a reasonable time frame, which has practical implications for large-scale industrial equipment modeling. Radiative cooling effects are accounted for using a discrete-ordinates model.
CASE STUDIES IN THERMAL ENGINEERING
(2023)
Article
Thermodynamics
Joo Hyun Moon, Jungho Lee, Seong Hyuk Lee
Summary: This study numerically investigates the characteristics of forced immersion quenching and finds that boiling and convective heat transfer are the main cooling mechanisms in this process. Under the action of a water jet, a large amount of vapor is generated at the surface of the hot steel specimen, but the amount of vapor decreases with increased water jet velocity, leading to improved cooling performance.
CASE STUDIES IN THERMAL ENGINEERING
(2022)
Article
Thermodynamics
Jianhong Zhou, Mingxiang Lu, Qi Zhao, Dinghua Hu, Hanshi Qin, Xuemei Chen
Summary: This study proposes a Contour Extraction Based on Topology Optimization (CEBTO) method to optimize the geometry of fins and improve the hydrothermal performance of Microchannel Heat Sinks (MCHS) under high Reynolds number (Re). The results show that the CEBTO-generated heat sinks have better overall performance compared to the conventional topology optimization (TO) designs.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Thermodynamics
D. Padrao, D. Hancock, J. Paterson, F. Schoofs, C. Tuck, I. Maskery
Summary: This study numerically analyzed the hydraulic and thermal performance of five surface-based lattice structures and developed predictive models for pressure drop and volumetric heat transfer coefficients. The research found that the thermal performance of the surface-based lattices is dependent on the internal geometry, with structures capable of distributing thermal energy across the entire fluid volume having higher heat transfer coefficients.
APPLIED THERMAL ENGINEERING
(2024)
Article
Thermodynamics
Nithin S. Panicker, Marc Olivier G. Delchini, Tom Sambor, Adrian S. Sabau
Summary: Modern HRSGs operating at high temperatures suffer from oxide formation inside heat exchanger tubes, which reduces heat recovery efficiency. The detachment of thick oxide scales causes erosion damage downstream. A CFD model was developed to predict fluid flow, heat transfer, and oxidation in HRSGs, while a Porous Media Model method was developed to model fin effects on heat transfer. The model was used to simulate a real-scale HRSG and identify regions requiring oxide-resistant coatings to prevent damages.
APPLIED THERMAL ENGINEERING
(2023)
Article
Chemistry, Analytical
Qiang Fu, Zenghao Liu, Shuaiqi Cao, Zhe Wang, Guojun Liu
Summary: A serpentine mixing unit model based on topology optimization is proposed to enhance reverse flow in both horizontal and vertical directions, which leads to a rapid increase in the mixing index. The proposed model is applied in a T-shaped micromixer to create a micromixer design named TOD, which shows outstanding mixing performance. Numerical simulations confirm that TOD has excellent mixing performance at both high and low Reynolds numbers, with mixing indexes beyond 90% for Re > 5.
Article
Computer Science, Artificial Intelligence
Marina Kontou, Dimitrios Kapsoulis, Ioannis Baklagis, Xenofon Trompoukis, Kyriakos Giannakoglou
Summary: A data-driven two-branch deep neural network called lambda-DNN is presented for predicting scalar fields. The network architecture consists of two separate branches connected to the main network, used in conjugate heat transfer analysis and shape optimization problems.
NEURAL COMPUTING & APPLICATIONS
(2022)
Article
Green & Sustainable Science & Technology
Vivek R. Pawar, Sarvenaz Sobhansarbandi
Summary: The study investigates the performance optimization of a heat pipe evacuated tube solar collector integrated with phase change materials under normal and on-demand operations. Results show that expedited phase change process and thermal storage enhancement were achieved under on-demand operation, while different PCMs exhibited varying energy storage capabilities and fin temperatures under different operating conditions. Recommending the use of specific PCM combinations for normal and on-demand operation to enhance system's thermal performance.
SUSTAINABLE ENERGY TECHNOLOGIES AND ASSESSMENTS
(2021)
Article
Environmental Sciences
M. C. S. Ferreira, B. Furieri, J. M. Santos, A. Ould El Moctar, J. -L. Harion, A. Valance, P. Dupont, N. C. Reis Jr
ENVIRONMENTAL FLUID MECHANICS
(2020)
Article
Mechanics
Talib Dbouk, Dimitris Drikakis
Article
Energy & Fuels
H. Karkaba, T. Dbouk, C. Habchi, S. Russeil, T. Lemenand, D. Bougeard
CHEMICAL ENGINEERING AND PROCESSING-PROCESS INTENSIFICATION
(2020)
Article
Thermodynamics
Guanghui Wang, Talib Dbouk, Dingbiao Wang, Yuanshuai Pei, Xu Peng, Honglin Yuan, Sa Xiang
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2020)
Article
Mechanics
Talib Dbouk, Dimitris Drikakis
Article
Environmental Sciences
Maria Clara S. Ferreira, Bruno Furieri, Cristina L. de Morais, Jamily F. Stocco, Neyval C. Reis Jr, Jean-Luc Harion, Jane Meri Santos
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2020)
Article
Mechanics
Talib Dbouk, Dimitris Drikakis
Article
Mechanics
Talib Dbouk, S. Amir Bahrani
Summary: For the first time, an Eulerian three-dimensional transient model was developed for thermal convection in immersed granular beds, successfully predicting local phenomena and introducing new concepts of critical Rayleigh number and critical temperature in the system.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2021)
Article
Mechanics
Talib Dbouk, Dimitris Drikakis
Summary: This study investigates the impact of air ventilation systems on airborne virus transmission in confined spaces using an elevator as a prototype. It shows that the position of inlets and outlets significantly influences flow circulation and droplet dispersion, and that air purifiers alone cannot eliminate airborne transmission. The practical conclusion is that the design and placement of air purifiers and ventilation systems play a crucial role in reducing droplet dispersion and airborne virus transmission within confined spaces.
Article
Mechanics
Talib Dbouk, Dimitris Drikakis
Summary: This study examines the impact of weather seasonality on virus transmission dynamics, introduces a new Airborne Infection Rate (AIR) index, and provides data evidence on how weather seasonality leads to two pandemic outbreaks per year.
Article
Mechanics
Talib Dbouk, Dimitris Drikakis
Summary: This study focuses on the noise induced by drone swarms, revealing that a V-flight formation emits less noise and induces reduced drag compared to a U-shape (or rectangular) formation, thus saving energy. The research has broad impacts on defense and security, public health, transportation, and surveillance, among other fields.
Article
Emergency Medicine
Talib Dbouk, Silvia Aranda-Garcia, Roberto Barcala-Furelos, Antonio Rodriguez-Nunez, Dimitris Drikakis
Summary: This study assesses the potential risk of airborne virus transmission during outdoor CPR, finding that factors such as wind direction, humidity, and temperature influence the level of risk. Rescuers are recommended to evaluate airborne infectious risk before starting CPR in open air and position themselves to avoid wind directed to their faces.
EMERGENCY MEDICINE JOURNAL
(2021)
Article
Mechanics
Talib Dbouk, Dimitris Drikakis
Summary: The study found that the data reported for the daily number of infected cases during the first wave of the COVID-19 pandemic were inaccurate due to insufficient tracing across the populations. To address the uncertainty of the first wave data, scientists proposed a physics-based model based on fluid dynamics simulations of weather effects, combining environmental seasonality-driven virus transmission rate with pandemic multiwave phenomena to improve data accuracy in statistical predictions.
Article
Mechanics
Talib Dbouk, Dimitris Drikakis
Summary: This study demonstrates how pollen grains may increase the transmission rate of coronavirus in a population, especially during seasons and environments with high pollen concentrations. It suggests that public authorities should reconsider social distancing guidelines, particularly during the spring pollination period.
Article
Multidisciplinary Sciences
Talib Dbouk, Dimitris Drikakis
Summary: The study found that the bending of endotracheal tubes inside the human trachea affects local fluid dynamics, which in turn impacts mechanical ventilation performance.
Article
Thermodynamics
Navid Freidoonimehr, Azadeh Jafari, Maziar Arjomandi
Summary: In this study, a high-fidelity flow visualisation technique is used to investigate the resemblance between a turbulent boundary layer generated by different tripping devices in a lab environment and a naturally developed canonical turbulent boundary layer. The study finds that the blockage created by trips is the main factor affecting the turbulence statistics at a certain downstream distance.
INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW
(2024)
Article
Thermodynamics
Yuning Wang, Alberto Solera-Rico, Carlos Sanmiguel Vila, Ricardo Vinuesa
Summary: This study proposes a method that combines 6-VAEs for modal decomposition and transformer neural networks for temporal-dynamics prediction in the latent space to develop reduced-order models (ROMs) for turbulent flows. The method achieves high reconstruction accuracy and accurate prediction of temporal dynamics.
INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW
(2024)
Article
Thermodynamics
L. Laguarda, S. Hickel, F. F. J. Schrijer, B. W. van Oudheusden
Summary: Wall-resolved large-eddy simulations were used to investigate the Reynolds number effects in supersonic turbulent boundary layers at Mach 2.0. The study covered a wide range of friction Reynolds numbers and identified trends in various statistics and scaling laws. The size and topology of turbulent structures in the boundary layer were examined, with a focus on the outer-layer motions at high Reynolds numbers. The study also assessed the influence of outer-layer structures on near-wall turbulence and the sensitivity of uniform momentum regions to compressibility.
INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW
(2024)
Article
Thermodynamics
A. Doehring, T. Kaller, S. J. Schmidt, N. A. Adams
Summary: In this study, well-resolved large-eddy simulations were used to investigate turbulent duct flows with a square cross section. The influence of a modified wall shear stress on the secondary flow was analyzed by artificially modifying the wall shear stress at one of the four walls. The results showed that the modification led to an asymmetrical distribution of the secondary flow source terms, affecting the momentum distribution. Furthermore, the anisotropy of the Reynolds stress tensor, which induces the secondary flow vortices, was significantly affected by the wall shear stress modulation.
INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW
(2024)
