Article
Engineering, Civil
Antonio J. Alvarez, Nelix Nieto, Kenny K. C. S. Kwok, Santiago Hernandez
Summary: A 2D URANS approach was used to numerically simulate the effects of free stream turbulence on bluff bodies, and the results showed good agreement with experimental data. This method can be used affordably to study aerodynamics problems related to free stream turbulence in wind engineering.
JOURNAL OF WIND ENGINEERING AND INDUSTRIAL AERODYNAMICS
(2023)
Article
Thermodynamics
Mattia Samiolo, Patrick G. Verdin
Summary: This paper introduces the use of computational fluid dynamics in studying the transition from thermal to electrical propulsion in vehicle design. It establishes a procedure to develop and evaluate a prototype heat exchanger, and uses numerical methods to assess the aerodynamic performance of an electric vehicle equipped with the new heat exchanger. The comparison shows a 5% reduction in drag and overall weight with the newly designed system, proposing a new form of heat exchanger packaging.
APPLIED THERMAL ENGINEERING
(2022)
Article
Engineering, Marine
Minsheng Zhao, Decheng Wan, Yangyang Gao
Summary: This study compares the numerical simulation of sheet/cloud cavitation around an NACA0012 hydrofoil using different turbulence models. The modified SST k-omega and Smagorinsky turbulence models performed better in capturing the unsteady cavitation vortex cluster, while the Smagorinsky model of the LES method provided specific information in the cavitation flow field. The vortex structure of the wing was identified as the main cause of cavitation shedding.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2021)
Article
Thermodynamics
Marielle de Oliveira, Rodolfo C. Puraca, Bruno S. Carmo
Summary: This study investigates the influence of numerical arrangement on the accuracy of NREL 5 MW wind turbine rotor performance evaluation using Computational Fluid Dynamics (CFD) methodology. Two different discretization schemes were used to handle the nonlinearity of the Navier-Stokes equation, and two turbulence closure models were employed for blade-resolved simulations. The CFD results were verified against the blade element momentum theory implemented in OpenFAST.
Article
Thermodynamics
Ashok K. Barik, Aurovinda Mohanty, Jnana R. Senapati, Mohamed M. Awad
Summary: In this study, the constructal theory was utilized to develop six new types of ribs for a solar air heater, and their performance was numerically investigated using computational fluid dynamics. It was found that the T-rib showed the highest Nusselt number and lowest friction factor among all considered ribs, leading to enhanced heat transfer efficiency in the solar air heater.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2021)
Article
Computer Science, Interdisciplinary Applications
Pratikkumar Raje, Krishnendu Sinha
Summary: The article discusses the limitations of the Menter SST k-omega turbulence model and proposes the SUQ-SST model as an improvement. The new model significantly improves predicting Reynolds stress anisotropy, flow separation, and surface properties.
COMPUTERS & FLUIDS
(2021)
Article
Engineering, Mechanical
Gearoid Farrell, Michael Gibbons, Tim Persoons
Summary: This study combines a synthetic jet actuator (SJA) and a leeward porous coating to modify the aerodynamic forces on a cylinder. The results show that the combination of SJA and porous coating can reduce the drag coefficient, especially when f(+) < 1. However, there is no significant advantage of the combined configuration when f(+) > 1. The use of porous coating alone is more effective.
Article
Physics, Fluids & Plasmas
Imogen Guinness, Tim Persoons
Summary: The study investigated the impact of leeward porous coatings on the drag of circular cylinders in cross-flow using numerical simulations. It found that partial leeward porous coatings caused an increase in pressure on the leeward side, reduced pressure and aerodynamic force fluctuations, and had a damping effect on vortex shedding. The study also showed a significant reduction in turbulence intensity at the outlet, leading to a drag reduction of 5-16% with the optimum configuration at a 7 degrees coating angle.
Article
Thermodynamics
Mahmoud Jourabian, Mehrdad Raeesi
Summary: This study analyzes the heat transfer performances of various water-based nanofluids in a 2D backward-facing step channel using the OpenFOAM package. The results show that low-concentration nanofluids can significantly enhance heat transfer while increasing resistance, while high-concentration nanofluids can be effective coolants under specific conditions.
NUMERICAL HEAT TRANSFER PART A-APPLICATIONS
(2023)
Article
Engineering, Multidisciplinary
Guang Yin, Muk Chen Ong, Puyang Zhang
Summary: Flow conditioners are used in pipeline systems for the offshore and subsea oil and gas industry to improve flow rate measurement accuracy. However, there is a lack of knowledge about the influence of these conditioners on flow inside a bend pipe due to measurement inaccuracy caused by complex geometries. In this study, numerical simulations are performed to investigate flow characteristics inside a double bend pipe and the performance of a conditioner with a bundle of 19 tubes. The results show that helical flow structures behind the double bend can be effectively eliminated by the flow conditioner. The performance of the conditioner is evaluated based on axial flow velocity profiles, swirl intensities, and deviation from flow in a straight pipe, and the effects of Reynolds numbers and tube bundle lengths on flow downstream the conditioner are discussed.
ENGINEERING APPLICATIONS OF COMPUTATIONAL FLUID MECHANICS
(2023)
Article
Construction & Building Technology
Feng Wang, Guoyi Jiang
Summary: This study systematically examined the wind loads on spherical structures with different apex-height-to-diameter ratios using a validated CFD model, providing insights into the suction effects and changes in drag and lift coefficients. The results indicated that the largest positive mean pressure coefficient at the windward surface increased with apex-height-to-diameter ratios, and a polynomial approximation function was derived for quickly determining the largest suction effect. Design suggestions based on the results were also provided.
Article
Mechanics
Veeresh Tekure, K. Venkatasubbaiah
Summary: Numerical study of conjugate heat transfer in supersonic turbulent flow over a flat plate with finite thickness shows lower interface temperature and fluid temperature variation compared to non-conjugate heat transfer analysis. Results indicate significant increase in interface temperature for low thermal conductivity plate materials, and negligible effect of plate thickness on flow field temperature variation. Additionally, the maximum interface temperature increases with plate thickness.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2021)
Article
Engineering, Marine
Xiumao Du, Peng Yuan, Junzhe Tan, Xiancai Si, Yonghui Liu, Shujie Wang, Xianpeng Lang
Summary: This study analyzes the influence of the support structure design on the performance of a diffuser-augmented hydrodynamic turbine. Blade-resolved Computational Fluid Dynamics (CFD) numerical simulations are used to analyze the effects of parameters such as support distance, the number of columns, and the aspect ratio of the support structure. The results show that support structures can significantly reduce the acceleration ratio and power coefficient of the turbine.
Article
Engineering, Chemical
Krzysztof Rogowski, Grzegorz Krolak, Galih Bangga
Summary: The research validates the aerodynamic performance of the NACA 0018 airfoil and characteristics of the laminar separation bubble, with a numerical study examining sensitivity of the model. The results provide insight into the potential development of turbulence models and their accuracy at low and moderate Reynolds numbers.
Article
Engineering, Civil
Erdinc Sogut, Deniz Velioglu Sogut, Ali Farhadzadeh
Summary: Through experiments and simulations, the study investigated the interactions of random waves with a cluster of structures, evaluating the performance of different turbulence models. The analysis showed the shortcomings of the k-omega SST model compared to the LES model.
COASTAL ENGINEERING
(2021)
Article
Mathematics, Applied
Saumil Patel, Paul Fischer, Misun Min, Ananias Tomboulides
JOURNAL OF SCIENTIFIC COMPUTING
(2019)
Article
Thermodynamics
G. K. Giannakopoulos, C. E. Frouzakis, P. F. Fischer, A. G. Tomboulides, K. Boulouchos
FLOW TURBULENCE AND COMBUSTION
(2020)
Article
Thermodynamics
George K. Giannakopoulos, Christos E. Frouzakis, Shikhar Mohan, Ananias G. Tomboulides, Moshe Matalon
COMBUSTION AND FLAME
(2019)
Editorial Material
Thermodynamics
Franck Nicoud, Stefan Hickel, Ananias Tomboulides, Wolfgang Rodi, Michael Leschziner
FLOW TURBULENCE AND COMBUSTION
(2020)
Article
Nuclear Science & Technology
Dillon R. Shaver, Nate Salpeter, Ananias Tomboulides, Prasad Vegendla, Adrian Tentner, W. David Pointer, Elia Merzari
NUCLEAR TECHNOLOGY
(2020)
Article
Computer Science, Hardware & Architecture
Tzanio Kolev, Paul Fischer, Misun Min, Jack Dongarra, Jed Brown, Veselin Dobrev, Tim Warburton, Stanimire Tomov, Mark S. Shephard, Ahmad Abdelfattah, Valeria Barra, Natalie Beams, Jean-Sylvain Camier, Noel Chalmers, Yohann Dudouit, Ali Karakus, Ian Karlin, Stefan Kerkemeier, Yu-Hsiang Lan, David Medina, Elia Merzari, Aleksandr Obabko, Will Pazner, Thilina Rathnayake, Cameron W. Smith, Lukas Spies, Kasia Swirydowicz, Jeremy Thompson, Ananias Tomboulides, Vladimir Tomov
Summary: Efficient exploitation of exascale architectures requires new numerical algorithms. CEED, a research partnership focused on developing next-generation discretization software, collaborates with various projects and institutions to optimize performance on large-scale GPU architectures and advance algorithms in fields such as unstructured adaptive mesh refinement and high-order data visualization.
INTERNATIONAL JOURNAL OF HIGH PERFORMANCE COMPUTING APPLICATIONS
(2021)
Article
Nuclear Science & Technology
Jun Fang, Dillon R. Shaver, Ananias Tomboulides, Misun Min, Paul Fischer, Yu-Hsiang Lan, Ronald Rahaman, Paul Romano, Sofiane Benhamadouche, Yassin A. Hassan, Adam Kraus, Elia Merzari
Summary: The text discusses the use of numerical simulations to study flow structure interactions and heat transfer processes in nuclear reactor cores. Through full-core simulation and reduced order methodology, the researchers are able to model the effects of spacer grids and mixing vanes without excessive costs. This advancement in capability may inspire further integration of high-fidelity numerical simulations in engineering designs.
NUCLEAR ENGINEERING AND DESIGN
(2021)
Article
Computer Science, Theory & Methods
Ahmad Abdelfattah, Valeria Barra, Natalie Beams, Ryan Bleile, Jed Brown, Jean-Sylvain Camier, Robert Carson, Noel Chalmers, Veselin Dobrev, Yohann Dudouit, Paul Fischer, Ali Karakus, Stefan Kerkemeier, Tzanio Kolev, Yu-Hsiang Lan, Elia Merzari, Misun Min, Malachi Phillips, Thilina Rathnayake, Robert Rieben, Thomas Stitt, Ananias Tomboulides, Stanimire Tomov, Vladimir Tomov, Arturo Vargas, Tim Warburton, Kenneth Weiss
Summary: This paper outlines the research and development activities in the Center for Efficient Exascale Discretization as part of the US Exascale Computing Project, focusing on state-of-the-art high-order finite-element algorithms for high-order applications on GPU-accelerated platforms. The authors discuss GPU developments in various components of the CEED software stack, and report performance and capability improvements in several CEED-enabled applications on both NVIDIA and AMD GPU systems.
PARALLEL COMPUTING
(2021)
Article
Energy & Fuels
Renos Rotas, Petros Iliadis, Nikos Nikolopoulos, Ananias Tomboulides, Elias Kosmatopoulos
Summary: Research on combined cooling heating power (trigeneration) systems with high renewable energy source contributions has increased rapidly, aligned with the European Union legislation. This study examines the operation of a trigeneration system in Greece and proposes design and control measures to optimize renewable energy generation. Simulation and validation results show significant improvements in solar and renewable energy contributions.
Editorial Material
Thermodynamics
Stefan Hickel, Maria Vittoria Salvetti, Wolfgang Rodi, Ananias Tomboulides, Michael Leschziner
FLOW TURBULENCE AND COMBUSTION
(2022)
Article
Computer Science, Theory & Methods
Paul Fischer, Stefan Kerkemeier, Misun Min, Yu-Hsiang Lan, Malachi Phillips, Thilina Rathnayake, Elia Merzari, Ananias Tomboulides, Ali Karakus, Noel Chalmers, Tim Warburton
Summary: This paper describes the development of NekRS, a GPU-oriented thermal-fluids simulation code based on the spectral element method (SEM). The code is designed for performance portability and leverages scalable developments in other libraries such as Nek5000 and libParanumal. The paper focuses on critical performance sections of the Navier-Stokes time advancement and presents performance results on multiple platforms.
PARALLEL COMPUTING
(2022)
Proceedings Paper
Engineering, Mechanical
Adrian Tentner, Prasad Vegendla, Ananias Tomboulides, Aleks Obabko, Elia Merzari, Dillon Shaver
PROCEEDINGS OF THE 26TH INTERNATIONAL CONFERENCE ON NUCLEAR ENGINEERING, 2018, VOL 8
(2018)
Proceedings Paper
Mechanics
G. K. Giannakopoulos, C. E. Frouzakis, M. Matalon, A. G. Tomboulides
DIRECT AND LARGE-EDDY SIMULATION X
(2018)
Proceedings Paper
Nuclear Science & Technology
Adrian Tentner, Prasad Vegendla, Ananias Tomboulides, Aleks Obabko, Elia Merzari, Dillon Shaver
PROCEEDINGS OF THE 25TH INTERNATIONAL CONFERENCE ON NUCLEAR ENGINEERING, 2017, VOL 8
(2017)
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)