scholarly journals Numerical modeling tools for transient electromagnetic problems

1990 ◽  
Author(s):  
D Riley ◽  
C Turner ◽  
L Bacon ◽  
J Kotulski
Keyword(s):  
Numerical Modeling ◽  
Modeling Tools ◽  
Electromagnetic Problems ◽  
Transient Electromagnetic

Finite-difference modeling of wave propagation and diffusion in poroelastic media

Geophysics ◽  
2009 ◽  
Vol 74 (4) ◽  
pp. T55-T66 ◽  
Author(s):  
Fabian Wenzlau ◽  
Tobias M. Müller
Keyword(s):  
Numerical Modeling ◽  
Finite Difference ◽  
Diffusion Processes ◽  
Spatial Scales ◽  
Rock Physics ◽  
Seismic Attenuation ◽  
Rock Properties ◽  
Modeling Tools ◽  
Reservoir Rocks ◽  
Poroelastic Media

Numerical modeling of seismic waves in heterogeneous, porous reservoir rocks is an important tool for interpreting seismic surveys in reservoir engineering. Various theoretical studies derive effective elastic moduli and seismic attributes from complex rock properties, involving patchy saturation and fractured media. To confirm and further develop rock-physics theories for reservoir rocks, accurate numerical modeling tools are required. Our 2D velocity-stress, finite-difference scheme simulates waves within poroelastic media as described by Biot’s theory. The scheme is second order in time, contains high-order spatial derivative operators, and is parallelized using the domain-decomposition technique. A series of numerical experiments that are compared to exact analytical solutions allow us to assess the stability conditions and dispersion relations of the explicit poroelastic finite-differ-ence method. The focus of the experiments is to model wave-induced flow accurately in the vicinity of mesoscopic heterogeneities such as cracks and gas inclusions in partially saturated rocks. For that purpose, a suitable numerical setup is applied to extract seismic attenuation and dispersion from quasi-static experiments. Our results confirm that finite-difference modeling is a valuable tool to simulate wave propa-gation in heterogeneous poroelastic media, provided the temporal and spatial scales of the propagating waves and of the induced fluid-diffusion processes are resolved properly.

Experimental and Numerical Modeling Tools for Conventional Hydropower Systems

2016 ◽  
pp. 448-464 ◽  
Author(s):  
Zhiqun Daniel Deng ◽  
Thomas J. Carlson ◽  
Gene R. Ploskey ◽  
Richard S. Brown ◽  
Gary E. Johnson ◽  
...  
Keyword(s):  
Numerical Modeling ◽  
Modeling Tools ◽  
Experimental And Numerical Modeling

NUMERICAL MODELING OF THE IMPACT OF QUARANTINE MEASURES ON THE DYNAMICS OF THE EPIDEMIOLOGICAL PROCESS BASED ON THE SEIRD MODEL

2021 ◽  
Vol 7 (2) ◽  
pp. 170-187
Author(s):  
Nina I. Eremeeva
Keyword(s):  
Mathematical Modeling ◽  
Numerical Modeling ◽  
Dynamic Models ◽  
Numerical Calculations ◽  
Short Term ◽  
Modeling Tools ◽  
Population Immunity ◽  
Restrictive Measures ◽  
The Impact

The COVID-19 epidemic has once again demonstrated the importance of predicting the development of various processes and calculating the consequences. “How effective is the introduction of strict quarantine measures?” and “Will the quarantine be able to stop the epide­mic?” — these questions still have no clear answer. This article aims to answer these questions using mathematical modeling tools using the SEIRD model, modified to account for the peculiarities of the spread of COVID-19. The SEIRD model belongs to the class of differential dynamic models, which allows quick experimentation to predict the spread of the disease and calculate its influence on the development of certain processes. Based on numerical modeling, the author demonstrates that insufficient quarantine measures provide only a temporary effect. After they end, with an insufficient level of “population immunity”, the epidemic starts growing again, leading to a second morbidity peak. This paper presents numerical calculations to track the duration impact and quarantine measures’ severity on the dynamics of the epidemiological process. The results show that strict restrictive measures are not always effective, and strict short-term measures have less effect than softer, but long-term measures. In addition, the author provides an example of finding the parameters of quarantine measures that ensure fixed limits on the morbidity level during the epidemic.

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