Article
Engineering, Marine
Luuk Barendse, Vera M. van Bergeijk, Weiqiu Chen, Jord J. Warmink, Aroen Mughal, Dorian Hill, Suzanne J. M. H. Hulscher
Summary: This study aims to determine the hydrodynamic conditions of the dike cover caused by wave run-up and overtopping flow using a numerical model. The model was calibrated based on resistance coefficients obtained from physical tests, and validated using other time series of the tests. The model results showed that pressure was the most influential hydrodynamic condition at the time of failure, and a certain porosity and thickness of the porous layer could significantly reduce peak pressure.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2022)
Article
Engineering, Aerospace
Imran Hayat, George Ilhwan Park
Summary: This research conducts wall-modeled large-eddy simulations to evaluate the predictive performance of three wall models in turbulent boundary layers subjected to spatially varying streamwise pressure gradients. It is found that all the wall models overpredict the skin friction in the region with a favorable pressure gradient. The overprediction in equilibrium and integral models is attributed to the deviation of mean velocity profiles from the log law, while for the PDE model, it is more pronounced due to a lack of correction for pressure gradients. Potential solutions to mitigate the problem are proposed.
Article
Mechanics
Sean P. Carney, Robert D. Moser
Summary: For wall-bounded turbulent shear flows with strong pressure gradients, an asymptotic model is developed to explain the effect of mean flow growth on small-scale near-wall turbulence, by performing asymptotic analysis of the Navier-Stokes equations.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Green & Sustainable Science & Technology
Brooke J. Stanislawski, Regis Thedin, Ashesh Sharma, Emmanuel Branlard, Ganesh Vijayakumar, Michael A. Sprague
Summary: As wind turbines become larger, the fluctuations in inflow have a significant impact on structural loading. The integral length scale, which represents the average size of the largest turbulent eddies, characterizes these fluctuations. Current design standards do not account for the varying integral length scales in turbine inflows. Using large-eddy simulations, we investigate the effects of turbulence with varying integral length scales on the loads of a 15-MW wind turbine. The results show that turbulence has a much greater impact on rotor and tower loads compared to mean shear profiles. Increasing the integral length scale can reduce blade root flapwise moments and rotor and tower loads. However, increasing the integral length scale beyond a certain point increases other loads and decreases some moments. Additionally, turbulence intensity has a larger influence on turbine loads than integral length scales. This study suggests that design standards should consider the varying integral length scales for accurate characterization of wind turbine loading in turbulent inflow conditions.
Article
Meteorology & Atmospheric Sciences
Aaron Wang, Ying Pan, Paul M. Markowski
Summary: This work investigates the impact of WENO schemes on the turbulence within LES simulations, finding that while WENO schemes have benefits for scalar advection in compressible models, they can have adverse effects on resolved turbulence when applied to momentum advection.
JOURNAL OF THE ATMOSPHERIC SCIENCES
(2021)
Article
Computer Science, Interdisciplinary Applications
Francesco De Vanna, Giacomo Baldan, Francesco Picano, Ernesto Benini
Summary: The study examines how numerical schemes and discretization approaches impact the outcomes of wall-resolved and wall-modeled LES. Utilizing a turbulent boundary layer setup over a flat plate in super- and hypersonic conditions, the effect of different numerical discretization strategies are demonstrated. The analysis reveals that the injected numerical viscosity significantly alters the wall dynamics, especially in wall-modeled arrangements, and suggests criteria for selecting a suitable numerical setup in wall-modeled LES.
COMPUTERS & FLUIDS
(2023)
Review
Engineering, Marine
Blanca Pena, Luofeng Huang
Summary: Ship operations are influenced by turbulent regimes that have a significant impact on hydrodynamic characteristics. Computational technologies have advanced to allow for detailed numerical simulations of turbulent ship flows, but the high computational costs and lack of updated recommendations for turbulence modeling present challenges. This paper reviews the current state-of-the-art turbulence modeling for ship hydrodynamic applications, introducing various approaches and discussing their applicability and limitations in different ship simulation scenarios. The goal is to provide guidance for CFD users in selecting turbulence modeling strategies and advancing the field.
Article
Meteorology & Atmospheric Sciences
Aaron Wang, Ying Pan, George H. Bryan, Paul M. Markowski
Summary: Large-eddy simulations (LES) frequently assume statistically steady and horizontally homogeneous conditions, which may lead to unrealistic results in simulating tornadoes. This study compares three different approaches to model near-surface turbulence in LES runs of tornado simulations and finds that the nonequilibrium approaches improve the accuracy of the results and better capture the characteristics of tornadoes.
MONTHLY WEATHER REVIEW
(2023)
Article
Energy & Fuels
Obula Reddy Kummitha, K. M. Pandey
Summary: The global demand for enhanced scramjet engine performance is increasing, with the main challenge being the mixing of fuel and air. Research has shown that using a wavy wall surface and double strut fuel injector can significantly improve mixing efficiency and combustion phenomenon.
Article
Thermodynamics
Francesco De Vanna, Matteo Bernardini, Francesco Picano, Ernesto Benini
Summary: This paper discusses the physical reliability of turbulence modeling in an adverse pressure gradient wall flow setup at moderate/high Reynolds number. The study compares wall-modeled and wall-resolved LES with DNS and experimental data to evaluate the wall modeling behavior. The results show that the proposed wall modeling strategy accurately describes the incoming and recovering boundary layers, but the recirculation region appears oversized compared to wall-resolved LES and experimental references.
INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW
(2022)
Article
Computer Science, Interdisciplinary Applications
T. Mukha, R. E. Bensow, M. Liefvendahl
Summary: The predictive accuracy of wall-modelled LES is influenced by the grid-cell type, with the use of prism cells near walls improving accuracy. Unstructured simulations may provide similar accuracy as simulations on structured grids, but the choice of base shape of near-wall cells impacts computational cost.
COMPUTERS & FLUIDS
(2021)
Article
Oceanography
Madelaine G. Rosevear, Bishakhdatta Gayen, Benjamin K. Galton-Fenzi
Summary: This study investigates the processes controlling ocean-driven melting of Antarctic ice shelves, finding a highly nonlinear melting response due to the effects of meltwater on ISOBL turbulence. Three distinct ISOBL regimes emerge based on current shear and buoyancy forcing strengths. By developing a novel regime diagram, insights into the varied melting responses around Antarctica are provided, emphasizing the need to include stratified and diffusive-convective dynamics in future basal melting parameterizations.
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2022)
Article
Mechanics
Dinar Zaripov, Vladislav Ivashchenko, Rustam Mullyadzhanov, Renfu Li, Nikolay Mikheev, Christian J. Kaehler
Summary: In this study, the mechanism of near-wall reverse flow (NWRF) events in turbulent duct flow at a relatively low Reynolds number Re-tau around 200 was investigated using direct numerical simulations and particle image velocimetry. A conceptual model was proposed to explain the formation of NWRF events, suggesting they are caused by intense hairpin vortices at the interface between high- and low-momentum flow regions. The similarity of flow topologies associated with NWRF events at Re-tau around 200 with those at higher Reynolds numbers indicates a generality of the proposed mechanism.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
Yongxiang Wu, Tristan Roemer, Gabriel Axtmann, Ulrich Rist
Summary: This study investigates the transition to turbulence induced by rotating cylindrical roughness pairs in a laminar boundary layer. It reveals the presence of stable inner vortices and streamwise vortices on the decelerated side, and analyzes the instability in the deceleration region and the wake.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Mechanics
Mitchell Fowler, Tamer A. Zaki, Charles Meneveau
Summary: A large eddy simulation wall model is developed based on a formal interpretation of quasi-equilibrium that governs momentum balance. The model includes a relaxation time scale that ensures self-consistency with assumed quasi-equilibrium conditions. The new approach allows for formally distinguishing between quasi-equilibrium and additional, non-equilibrium contributions to wall stress.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Mechanics
Saleh Rezaeiravesh, Ricardo Vinuesa, Mattias Liefvendahl, Philipp Schlatter
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2018)
Article
Mechanics
S. Rezaeiravesh, M. Liefvendahl
Correction
Mechanics
S. Rezaeiravesh, M. Liefvendahl
Article
Computer Science, Interdisciplinary Applications
S. Rezaeiravesh, T. Mukha, M. Liefvendahl
COMPUTERS & FLUIDS
(2019)
Article
Computer Science, Interdisciplinary Applications
T. Mukha, R. E. Bensow, M. Liefvendahl
Summary: The predictive accuracy of wall-modelled LES is influenced by the grid-cell type, with the use of prism cells near walls improving accuracy. Unstructured simulations may provide similar accuracy as simulations on structured grids, but the choice of base shape of near-wall cells impacts computational cost.
COMPUTERS & FLUIDS
(2021)
Article
Computer Science, Interdisciplinary Applications
Saleh Rezaeiravesh, Ricardo Vinuesa, Philipp Schlatter
Summary: This study aims to evaluate the accuracy, robustness, and sensitivity of scale-resolving simulations of turbulent channel flow by applying different metrics and comparing the performance of Nek5000 and OpenFOAM in terms of numerical parameters. The results indicate that Nek5000 outperforms OpenFOAM, and increasing numerical dissipation in OpenFOAM decreases uncertainties at the cost of accuracy. The influence of filtering in Nek5000 is found to be more complex and dependent on grid resolution.
COMPUTERS & FLUIDS
(2021)
Article
Engineering, Multidisciplinary
Silje Kreken Almeland, Timofey Mukha, Rickard E. Bensow
Summary: This work explores the application of an air entrainment model in simulation of flows in stepped spillways, identifying deficiencies and proposing improvements to the model. Two criteria for predicting the inception point of air entrainment are tested, with the boundary layer-based approach recommended for its superior accuracy and robustness.
APPLIED MATHEMATICAL MODELLING
(2021)
Article
Computer Science, Interdisciplinary Applications
Y. Morita, S. Rezaeiravesh, N. Tabatabaei, R. Vinuesa, K. Fukagata, P. Schlatter
Summary: The study demonstrates the flexibility, efficiency, and versatility of the BO-GPR approach in CFD applications, highlighting advantages such as diverse optimization problems, independence of the approach, ease of using different CFD solvers, and requiring a relatively small number of flow simulations.
JOURNAL OF COMPUTATIONAL PHYSICS
(2022)
Article
Computer Science, Interdisciplinary Applications
S. Rezaeiravesh, R. Vinuesa, P. Schlatter
Summary: This study combines various existing uncertainty quantification techniques to develop a framework for assessing metrics in computational physics problems, such as accuracy, sensitivity, and robustness. The framework analyzes the relationship between the simulator's outputs and uncertain inputs and parameters to enhance our understanding of different factors in physics simulations.
JOURNAL OF COMPUTATIONAL SCIENCE
(2022)
Article
Mechanics
Jie Yao, Saleh Rezaeiravesh, Philipp Schlatter, Fazle Hussain
Summary: This study conducted direct numerical simulations of flow in a smooth circular pipe and obtained various turbulence statistics. A comparison with other simulations and experiments revealed small but noticeable differences. The friction factor deviated from the Prandtl friction law at low and high Reynolds numbers. The wall shear stress fluctuations and axial turbulence intensity in the pipe were lower than in the channel, but the difference decreased with increasing Reynolds number.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Mechanics
S. Rezaeiravesh, T. Mukha, P. Schlatter
Summary: Multifidelity models (MFMs) are used to construct predictive models for flow quantities of interest (QoIs) over uncertain/design parameters, for the purpose of uncertainty quantification, data fusion, and optimization. The hierarchical MFM strategy allows for simultaneous calibration of fidelity-specific parameters in a Bayesian framework, combining lower and higher-fidelity data in an optimal way to provide improved prediction and confidence intervals for QoIs.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Engineering, Marine
Timofey Mukha, Rickard E. Bensow
Article
Computer Science, Interdisciplinary Applications
Usman Riaz, E. Seegyoung Seol, Robert Hager, Mark S. Shephard
Summary: The accurate representation and effective discretization of a problem domain into a mesh are crucial for achieving high-quality simulation results and computational efficiency. This work presents recent developments in extending an automated tokamak modeling and meshing infrastructure to better support the near flux field following meshing requirements of the XGC Gyro-kinetic Code.
COMPUTER PHYSICS COMMUNICATIONS
(2024)
Article
Computer Science, Interdisciplinary Applications
Zhenglu Li, Gabriel Antonius, Yang-Hao Chan, Steven G. Louie
Summary: This article presents a workflow for practical calculations of electron-phonon coupling and includes the effect of many-electron correlations using GW perturbation theory. The workflow combines different software packages to enable accurate calculations at the level of quasiparticle band structures.
COMPUTER PHYSICS COMMUNICATIONS
(2024)
Article
Computer Science, Interdisciplinary Applications
Akihiro Koide, Sara Rabouli, Pierre Le Meur, Sylvain Tricot, Philippe Schieffer, Didier Sebilleau, Calogero R. Natoli
Summary: We present the MsSpec Atomic Scattering Amplitude Package (MASAP), which includes a computation program and a graphical interface for generating atomic scattering amplitude (ASA). The study investigates the applicability of plane wave (PW) and curved spherical wave (SW) scattering in describing electron propagation. The results show that the imaginary part of the optical potential enhances the elastic scattering in the forward direction but causes damping effects in other directions.
COMPUTER PHYSICS COMMUNICATIONS
(2024)
Article
Computer Science, Interdisciplinary Applications
A. Bagci, Gustavo A. Aucar
Summary: The electron repulsion integrals over Slater-type orbitals with non-integer principal quantum numbers are investigated in this study. These integrals are important in calculations of many-electron systems. New relationships free from hyper-geometric functions are derived to simplify the calculations. With the use of auxiliary functions and straightforward recurrence relationships, these integrals can be efficiently computed, providing initial conditions for the evaluation of expectation values and potentials.
COMPUTER PHYSICS COMMUNICATIONS
(2024)
Article
Computer Science, Interdisciplinary Applications
Andrzej Daniluk
Summary: RHEED_DIFF_2D is an open-source software for qualitative numerical simulations of RHEED oscillation intensity changes with layer deposition, used for interpreting heteroepitaxial structures under different scattering crystal potential models.
COMPUTER PHYSICS COMMUNICATIONS
(2024)
Article
Computer Science, Interdisciplinary Applications
Niklas Kuehl, Hendrik Fischer, Michael Hinze, Thomas Rung
Summary: The article presents a strategy and algorithm for simulation-accompanying, incremental Singular Value Decomposition (SVD) for time-evolving, spatially parallel discrete data sets. The proposed method improves computational efficiency by introducing a bunch matrix, resulting in higher accuracy and practical applicability.
COMPUTER PHYSICS COMMUNICATIONS
(2024)
Article
Computer Science, Interdisciplinary Applications
Jose M. Rodriguez-Borbon, Xian Wang, Adrian P. Dieguez, Khaled Z. Ibrahim, Bryan M. Wong
Summary: This paper presents an open-source software package called TRAVOLTA for massively parallelized quantum optimal control calculations on GPUs. The TRAVOLTA package is an improvement on the previous NIC-CAGE algorithm and incorporates algorithmic improvements for faster convergence. Three different variants of GPU parallelization are examined to evaluate their performance in constructing optimal control fields in various quantum systems. The benchmarks show that the GPU-enhanced TRAVOLTA code produces the same results as previous CPU-based algorithms but with a speedup of more than ten times. The GPU enhancements and algorithmic improvements allow large quantum optimal control calculations to be efficiently executed on modern multi-core computational hardware.
COMPUTER PHYSICS COMMUNICATIONS
(2024)
Article
Computer Science, Interdisciplinary Applications
Weijie Hua
Summary: This work introduces a program called MCNOX for computing and analyzing ultrafast nonlinear X-ray spectra. It is designed for cutting-edge applications in photochemistry/photophysics enabled by X-ray free-electron lasers and high harmonic generation light sources. The program can calculate steady-state X-ray absorption spectroscopy and three types of ultrafast nonlinear X-ray spectra, and it is capable of identifying major electronic transitions and providing physical and chemical insights from complex signals.
COMPUTER PHYSICS COMMUNICATIONS
(2024)
Article
Computer Science, Interdisciplinary Applications
Leandro Benatto, Omar Mesquita, Lucimara S. Roman, Rodrigo B. Capaz, Graziani Candiotto, Marlus Koehler
Summary: Photoluminescence Quenching Simulator (PLQ-Sim) is a user-friendly software for studying the dynamics of photoexcited states at the interface between organic semiconductors. It provides important information on organic photovoltaic and photothermal devices and calculates transfer rates and quenching efficiency.
COMPUTER PHYSICS COMMUNICATIONS
(2024)
Article
Computer Science, Interdisciplinary Applications
Dongming Li, James Kestyn, Eric Polizzi
Summary: This study introduces a practical and efficient approach to calculate the all-electron full potential band structure in real space using a finite element basis. Instead of the k-space method, this method solves the Kohn-Sham equation self-consistently within a larger finite system enclosing the unit-cell. Non-self-consistent calculations are then performed in the Brillouin zone to obtain the band structure results, which are found to be in excellent agreement with the pseudopotential k-space method. Furthermore, the study successfully observes the band bending of core electrons.
COMPUTER PHYSICS COMMUNICATIONS
(2024)
Article
Computer Science, Interdisciplinary Applications
R. Kleiber, M. Borchardt, R. Hatzky, A. Koenies, H. Leyh, A. Mishchenko, J. Riemann, C. Slaby, J. M. Garcia-Regana, E. Sanchez, M. Cole
Summary: This paper describes the current state of the EUTERPE code, focusing on the implemented models and their numerical implementation. The code is capable of solving the multi-species electromagnetic gyrokinetic equations in a three-dimensional domain. It utilizes noise reduction techniques and grid resolution transformation for efficient computation. Additionally, various hybrid models are implemented for comparison and the study of plasma-particle interactions. The code is parallelized for high scalability on multiple CPUs.
COMPUTER PHYSICS COMMUNICATIONS
(2024)
Article
Computer Science, Interdisciplinary Applications
Pengliang Yang
Summary: This paper presents an open source software called SMIwiz, which combines seismic modelling, reverse time migration, and full waveform inversion into a unified computer implementation. SMIwiz supports both 2D and 3D simulations and provides various computational recipes for efficient calculation. Its independent processing and batchwise job scheduling ensure scalability, and its viability is demonstrated through applications on benchmark models.
COMPUTER PHYSICS COMMUNICATIONS
(2024)
Article
Computer Science, Interdisciplinary Applications
Christian Tantardini, Miroslav Ilias, Matteo Giantomassi, Alexander G. Kvashnin, Valeria Pershina, Xavier Gonze
Summary: Material discovery has been an active research field, and this study focuses on developing pseudopotentials for actinides and super-heavy elements. These pseudopotentials are crucial for accurate first-principles calculations and simulations.
COMPUTER PHYSICS COMMUNICATIONS
(2024)
Article
Computer Science, Interdisciplinary Applications
S. Blanes, F. Casas, C. Gonzalez, M. Thalhammer
Summary: This paper explores the extension of modified potential operator splitting methods to specific classes of nonlinear evolution equations. Numerical experiments confirm the advantages of the proposed fourth-order modified operator splitting method over traditional splitting methods in dealing with Gross-Pitaevskii systems.
COMPUTER PHYSICS COMMUNICATIONS
(2024)
Article
Computer Science, Interdisciplinary Applications
Siegfried Kaidisch, Thomas U. Hilger, Andreas Krassnigg, Wolfgang Lucha
Summary: Motivated by a use case in theoretical hadron physics, this paper revisits an application of a pole-sum fit to dressing functions of a confined quark propagator. Specifically, it investigates approaches to determine the number and positions of singularities closest to the origin for a function known numerically on a specific grid on the positive real axis. Comparing the efficiency of standard techniques to a pure artificial-neural-network approach and a combination of both, it finds that the combined approach is more efficient. This approach can be applied to similar situations where the positions of poles need to be estimated quickly and reliably from real-axis information alone.
COMPUTER PHYSICS COMMUNICATIONS
(2024)