Article
Engineering, Multidisciplinary
Misael Dalbosco, Thiago A. Carniel, Eduardo A. Fancello, Gerhard A. Holzapfel
Summary: The multiscale framework combined with the embedded elements technique was used to simulate four different RVEs resembling the microstructure of the arterial wall, showing that the periodic boundary condition converged faster and was less prone to concentrated effects at the boundaries of the RVE. The resulting microscopic strain fields were heterogeneous, with some values significantly larger than the macroscopic strain, which could help shed light on mechanotransduction mechanisms in fibrous tissues like arteries.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2021)
Review
Computer Science, Interdisciplinary Applications
Juan M. Gimenez, Sergio R. Idelsohn, Eugenio Onate, Rainald Lohner
Summary: A multiscale approach combining a novel representative volume element (RVE) with the Pseudo Direct Numerical Simulation (P-DNS) method is presented for simulating water droplets in turbulent airflow. Numerical experiments are carried out to study turbulence modulation phenomenon and a synthetic model is developed based on these experiments for global scale simulations of flows with airborne droplets via the P-DNS method. Improved predictions are obtained for flow conditions where turbulence modulation is noticeable.
ARCHIVES OF COMPUTATIONAL METHODS IN ENGINEERING
(2021)
Article
Engineering, Environmental
Marco Bacci, Jonas Sukys, Peter Reichert, Simone Ulzega, Carlo Albert
Summary: Due to limited knowledge about complex environmental systems, predicting their behavior under different scenarios or decision alternatives is uncertain. Considering, quantifying, and communicating this uncertainty is important for societal decisions. Stochastic models are often necessary to adequately describe uncertainty, but calibrating these models presents methodological and numerical challenges. To address this, we compare three numerical approaches and find that their performance is comparable for analyzing a stochastic hydrological model with hydrological data, suggesting that generality and practical considerations can guide technique choice for specific applications.
STOCHASTIC ENVIRONMENTAL RESEARCH AND RISK ASSESSMENT
(2023)
Article
Engineering, Mechanical
Ricardo Franco, Cesar Celis, Luis Fernando Figueira da Silva
Summary: Many engineering applications involve turbulent flows around bluff bodies, which feature unique turbulence-related phenomena. This study investigates three turbulence modeling approaches for a circular bluff body flow configuration: Reynolds-averaged Navier-Stokes (RANS), large eddy simulation (LES), and hybrid RANS/LES. Experimental comparison shows that RANS overestimates the recirculating bubble length and fails to accurately describe turbulent kinetic energy and flow anisotropy, while LES, DDES, and IDDES perform well in predicting these parameters. Scale resolving models reproduce the normalized anisotropy tensor invariants maxima in the shear layer but fail to capture local extrema within the wake recirculation region.
JOURNAL OF THE BRAZILIAN SOCIETY OF MECHANICAL SCIENCES AND ENGINEERING
(2023)
Article
Computer Science, Interdisciplinary Applications
Vit Dolejsi, Magnus Svard
Summary: The aim of this study is to evaluate a recently proposed model for viscous and heat conducting compressible fluids and compare it with the Navier-Stokes model. By accurately simulating a suite of test cases and comparing various measures, it was found that both models exhibit remarkable similarity when alpha equals 1, with differences typically around 1%.
JOURNAL OF COMPUTATIONAL PHYSICS
(2021)
Article
Chemistry, Physical
Mauricio J. del Razo, Manuel Dibak, Christof Schuette, Frank Noe
Summary: A novel approach, MSM/RD, is developed to simulate protein-ligand systems at large time and length scales by coupling Markov state models of molecular kinetics with particle-based reaction-diffusion simulations. The framework is capable of modeling protein-protein interactions and handling multiple molecules, addressing limitations such as isotropic ligands and single conformational states. The code has been published for reproducibility.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Multidisciplinary Sciences
D. Ye, L. Veen, A. Nikishova, J. Lakhlili, W. Edeling, O. O. Luk, V. V. Krzhizhanovskaya, A. G. Hoekstra
Summary: Uncertainty quantification is a key component in computational models involving uncertainties, and this work presents uncertainty quantification patterns designed to support the analysis of uncertainty in coupled multi-scale and multi-domain applications. The UQPs provide basic building blocks for tailored uncertainty quantification in multiscale models.
PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
(2021)
Article
Computer Science, Interdisciplinary Applications
Victor Trappler, Elise Arnaud, Arthur Vidard, Laurent Debreu
Summary: Classical calibration methods involve minimizing an objective function with control parameters to reduce errors between observations and results from a numerical model. When uncontrollable random inputs are present, the objective function becomes a random variable, requiring the introduction of robustness concepts. This paper presents a method to account for uncertainties by defining relative-regret and controlling it to adjust the robustness of estimators with respect to random inputs.
JOURNAL OF COMPUTATIONAL PHYSICS
(2021)
Article
Thermodynamics
Farid Rousta, Bamdad Lessani
Summary: This study investigates the effect of fluid Prandtl number on the thermal characteristics of a hydrodynamically fully developed turbulent channel flow. The numerical results show that increasing the Prandtl number accelerates the thermal development of turbulent flows towards their asymptotic fully developed state. Additionally, the development of temperature-velocity correlations and temperature variance distribution is found to be a good indicator of the flow reaching its thermally fully developed condition.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Mechanics
Linmin Li, Zhengdong Wang, Xiaojun Li, Zuchao ZhU
Summary: This study aims to develop a multiscale model to directly resolve large-scale cavities and model small discrete bubbles in tip-leakage cavitating flow. By using the volume of fluid (VOF) method, the Schnerr-Sauer cavitation model, and a discrete bubble model (DBM), better agreements and specific phenomena can be obtained in simulation compared to the macroscale model. The scale adaptive simulation approach is used for turbulence modeling in the transitions between different scales.
Article
Computer Science, Interdisciplinary Applications
Soonpil Kang, Arif Masud
Summary: This paper presents an immersed boundary method for weak enforcement of Dirichlet boundary conditions on immersed surfaces. The method combines the Variational Multiscale Discontinuous Galerkin method and an interface stabilized form. A significant contribution of this work is the analytically derived Lagrange multiplier for weak enforcement of the Dirichlet boundary conditions. Numerical experiments demonstrate the method's effectiveness with different types of meshes, and the norm of the stabilization tensor varies with the flow physics.
JOURNAL OF COMPUTATIONAL PHYSICS
(2022)
Article
Biotechnology & Applied Microbiology
Matias Inostroza, Andres Utrera, Claudio M. Garcia-Herrera, Eugenio Rivera, Diego J. Celentano, Emilio A. Herrera
Summary: This study analyzes the impact of geometrical features on the estimation of circumferential residual stresses in arteries. A specific sample of lamb abdominal artery is chosen for analysis and computational tools are used to capture the stress-free geometry. Numerical simulations are then used to reconstruct the sample and estimate the circumferential residual stresses. The results show significant differences in geometric features and residual stresses between idealized and realistic models, indicating the importance of considering more geometrical variables.
FRONTIERS IN BIOENGINEERING AND BIOTECHNOLOGY
(2023)
Article
Mechanics
Yohei Morii, Toshihiro Kawakatsu
Summary: A general multiscale and multiphysics simulation framework is proposed for inhomogeneous viscoelastic and elastoplastic complex flows, integrating macroscopic particle simulations with microscopic simulators to evaluate local stress. The platform combines SPH method and microscopic molecular simulators, allowing for simulation of complex flows with deformable objects. Dynamic switching of microscopic models and appropriate boundary conditions enable accurate simulations, demonstrating good quantitative agreement with experimental results.
Article
Economics
Saeed Mohammadian, Zuduo Zheng, Md Mazharul Haque, Ashish Bhaskar
Summary: This paper conducts a comprehensive benchmarking study on single-pipe continuum models for freeway traffic, selecting the best representative models for assessment based on traffic data from the German A5 autobahn.
TRANSPORTATION RESEARCH PART B-METHODOLOGICAL
(2021)
Review
Computer Science, Interdisciplinary Applications
N. Cheimarios, G. Kokkoris, A. G. Boudouvis
Summary: Chemical vapor deposition (CVD) is a well-established process for producing thin solid films for industrial and scientific applications for over 30 years. It is a multiscale process involving both cm to m scale reactors and micro-/nano- to atomic-scale deposited films. Various multiscale models and methodologies have been proposed over the years for the design, analysis, and optimization of the CVD process.
ARCHIVES OF COMPUTATIONAL METHODS IN ENGINEERING
(2021)
