Quantifying urban river–aquifer fluid exchange processes: A multi-scale problem

2007 ◽  
Vol 91 (1-2) ◽  
pp. 58-80 ◽  
Author(s):  
Paul A. Ellis ◽  
Rae Mackay ◽  
Michael O. Rivett
Keyword(s):  
Urban River ◽  
Scale Problem ◽  
Fluid Exchange ◽  
Multi Scale ◽  
Exchange Processes

scholarly journals ANALYSIS OF MULTI-SCALE PROBLEM ABOUT ANTENNA MOUNTED ON ELECTRICALLY LARGE PLATFORM BY USING CONNECTED EPA-PO

2012 ◽  
Vol 126 ◽  
pp. 169-183 ◽  
Author(s):  
Kaizhi Zhang ◽  
Jun Ou Yang ◽  
Feng Yang ◽  
Jian Zhang ◽  
Yan Li
Keyword(s):  
Scale Problem ◽  
Multi Scale ◽  
Large Platform

Dust Formation in Substellar Atmospheres: A Multi-Scale Problem

2006 ◽  
pp. 503-509
Author(s):  
Christiane Helling ◽  
Peter Woitke ◽  
Rupert Klein ◽  
Erwin Sedlmayr
Keyword(s):  
Dust Formation ◽  
Scale Problem ◽  
Multi Scale

scholarly journals A nonlinear multi-scale model for blood circulation in a realistic vascular system

2021 ◽  
Vol 8 (12) ◽  
Author(s):  
Ulin Nuha A. Qohar ◽  
Antonella Zanna Munthe-Kaas ◽  
Jan Martin Nordbotten ◽  
Erik Andreas Hanson
Keyword(s):  
Blood Flow ◽  
Blood Circulation ◽  
Vascular System ◽  
Scale Model ◽  
Model Framework ◽  
Fluid Exchange ◽  
Multi Scale ◽  
Proposed Model ◽  
Porous Media Model ◽  
Capillary Bed

In the last decade, numerical models have become an increasingly important tool in biological and medical science. Numerical simulations contribute to a deeper understanding of physiology and are a powerful tool for better diagnostics and treatment. In this paper, a nonlinear multi-scale model framework is developed for blood flow distribution in the full vascular system of an organ. We couple a quasi one-dimensional vascular graph model to represent blood flow in larger vessels and a porous media model to describe flow in smaller vessels and capillary bed. The vascular model is based on Poiseuille’s Law, with pressure correction by elasticity and pressure drop estimation at vessels' junctions. The porous capillary bed is modelled as a two-compartment domain (artery and venous) using Darcy’s Law. The fluid exchange between the artery and venous capillary bed compartments is defined as blood perfusion. The numerical experiments show that the proposed model for blood circulation: (i) is closely dependent on the structure and parameters of both the larger vessels and of the capillary bed, and (ii) provides a realistic blood circulation in the organ. The advantage of the proposed model is that it is complex enough to reliably capture the main underlying physiological function, yet highly flexible as it offers the possibility of incorporating various local effects. Furthermore, the numerical implementation of the model is straightforward and allows for simulations on a regular desktop computer.

scholarly journals Homogenization of trabecular structures

2020 ◽  
Vol 310 ◽  
pp. 00041
Author(s):  
Tomáš Krejčí ◽  
Aleš Jíra ◽  
Luboš Řehounek ◽  
Michal Šejnoha ◽  
Jaroslav Kruis ◽  
...  
Keyword(s):  
Finite Element ◽  
Effective Properties ◽  
Macro Level ◽  
Truss Structures ◽  
Scale Analysis ◽  
Scale Problem ◽  
Meso Level ◽  
Multi Scale ◽  
Macro Scale ◽  
Multi Scale Analysis

Numerical modeling of implants and specimens made from trabecular structures can be difficult and time-consuming. Trabecular structures are characterized as spatial truss structures composed of beams. A detailed discretization using the finite element method usually leads to a large number of degrees of freedom. It is attributed to the effort of creating a very fine mesh to capture the geometry of beams of the structure as accurately as possible. This contribution presents a numerical homogenization as one of the possible methods of trabecular structures modeling. The proposed approach is based on a multi-scale analysis, where the whole specimen is assumed to be homogeneous at a macro-level with assigned effective properties derived from an independent homogenization problem at a meso-level. Therein, the trabecular structure is seen as a porous or two-component medium with the metal structure and voids filled with the air or bone tissue at the meso-level. This corresponds to a two-level finite element homogenization scheme. The specimen is discretized by a reasonable coarse mesh at the macro-level, called the macro-scale problem, while the actual microstructure represented by a periodic unit cell is discretized with sufficient accuracy, called the meso-scale problem. Such a procedure was already applied to modeling of composite materials or masonry structures. The application of this multi-scale analysis is illustrated by a numerical simulation of laboratory compression tests of trabecular specimens.

scholarly journals The Framework for Rapid Graphics Application Development: The Multi-scale Problem Visualization

2015 ◽  
Vol 51 ◽  
pp. 2729-2733 ◽  
Author(s):  
Alexey Bezgodov ◽  
Andrey Karsakov ◽  
Aleksandr Zagarskikh ◽  
Vladislav Karbovskii
Keyword(s):  
Scale Problem ◽  
Application Development ◽  
Multi Scale

scholarly journals Predictive methods for computational metalloenzyme redesign – a test case with carboxypeptidase A

2016 ◽  
Vol 18 (46) ◽  
pp. 31744-31756 ◽  
Author(s):  
Crystal E. Valdez ◽  
Amanda Morgenstern ◽  
Mark E. Eberhart ◽  
Anastassia N. Alexandrova
Keyword(s):  
Test Case ◽  
Scale Problem ◽  
Carboxypeptidase A ◽  
Multi Scale ◽  
Predictive Methods ◽  
Metalloenzyme Design

Computational metalloenzyme design is a multi-scale problem.

scholarly journals Measuring methods for groundwater – surface water interactions: a review

2006 ◽  
Vol 10 (6) ◽  
pp. 873-887 ◽  
Author(s):  
E. Kalbus ◽  
F. Reinstorf ◽  
M. Schirmer
Keyword(s):  
Surface Water ◽  
Surface Waters ◽  
River Basin Management ◽  
Riparian Ecosystems ◽  
Major Research ◽  
Basin Management ◽  
Spatial And Temporal Scales ◽  
Measuring Methods ◽  
Multi Scale ◽  
Exchange Processes

Abstract. Interactions between groundwater and surface water play a fundamental role in the functioning of riparian ecosystems. In the context of sustainable river basin management it is crucial to understand and quantify exchange processes between groundwater and surface water. Numerous well-known methods exist for parameter estimation and process identification in aquifers and surface waters. Only in recent years has the transition zone become a subject of major research interest; thus, the need has evolved for appropriate methods applicable in this zone. This article provides an overview of the methods that are currently applied and described in the literature for estimating fluxes at the groundwater – surface water interface. Considerations for choosing appropriate methods are given including spatial and temporal scales, uncertainties, and limitations in application. It is concluded that a multi-scale approach combining multiple measuring methods may considerably constrain estimates of fluxes between groundwater and surface water.

scholarly journals A multi-scale flow model for blood regulation in a realistic vascular system

2020 ◽  
Author(s):  
Ulin Nuha Abdul Qohar ◽  
Antonella Zanna Munthe-Kaas ◽  
Jan Martin Nordbotten ◽  
Erik Andreas Hanson
Keyword(s):  
Blood Flow ◽  
Blood Circulation ◽  
Numerical Models ◽  
Scale Model ◽  
Fluid Exchange ◽  
Desktop Computer ◽  
Multi Scale ◽  
Proposed Model ◽  
Porous Media Model ◽  
Capillary Bed

Abstract In the last decade, numerical models have been an increasingly important tool in medical science both for the fundamental understanding of the physiology of the human body as well as for diagnostics and personalized medicine. In this paper, a multi-scale model is developed for blood flow and regulation in a full vascular structure of an organ. We couple a 1D vascular graph model to represent blood flow in larger vessels and a porous media model to describe flow in smaller vessels and capillary bed. The vascular model is based on Poiseuille’s law, with pressure correction by elasticity and pressure drop estimation at vessels junctions. The porous capillary bed is modeled as a two compartments domain (arterial and venal) and Darcy’s law. The fluid exchange between the arterial and venal capillary bed compartments is defined as blood perfusion. The numerical experiments show that the proposed model for blood circulation: 1) is closely dependent on the structure and parameters of both the vascular vessels and of the capillary bed, and 2) it provides a realistic blood circulation in the organ. The advantage of the proposed model is that it is complex enough to capture the underlying physiology reliably, yet highly flexible as it offers the possibility of incorporating various local effects. Furthermore, the numerical implementation of the model is straightforward and allows for simulations on a regular desktop computer.

scholarly journals Multi-scale transport and exchange processes in the atmosphere over mountains

2020 ◽  
Author(s):  
Stefano Serafin ◽  
Mathias W. Rotach ◽  
Marco Arpagaus ◽  
Ioana Colfescu ◽  
Joan Cuxart ◽  
...  
Keyword(s):  
Multi Scale ◽  
Exchange Processes
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