Experimental and Numerical Analysis of Membrane-Patterned Meta-Materials

2012 ◽  
Author(s):  
Emmanuel Ayorinde ◽  
Mohammad Al-Zubi ◽  
Akif Dundar ◽  
Gary Witus
Keyword(s):  
Numerical Analysis ◽  
Analytical Study ◽  
Frequency Dependent

Meta-materials show unconventional properties by virtue of their construction which normally includes physically-periodic formations. Various responses of these materials manifest frequency-dependent occurrences of significantly-enhanced and significantly-attenuated values, thus facilitating a wealth of design possibilities. The analysis of these structures presents non-trivial challenges, hence only very simple types are presently under analytical study. In this paper, a formation which includes patterned membrane fillings is explored experimentally and numerically to see if and how well such a construction may be utilized for meta-material applications.

scholarly journals Multiscaling of porous soils as heterogeneous complex networks

2008 ◽  
Vol 15 (6) ◽  
pp. 893-902 ◽  
Author(s):  
A. Santiago ◽  
J. P. Cárdenas ◽  
J. C. Losada ◽  
R. M. Benito ◽  
A. M. Tarquis ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Analytical Study ◽  
Preferential Attachment ◽  
Scaling Exponents ◽  
Pore Networks ◽  
Soil Model ◽  
Simulation Results ◽  
Porous Soils ◽  
Pore Properties ◽  
Good Agreement

Abstract. In this paper we present a complex network model based on a heterogeneous preferential attachment scheme to quantify the structure of porous soils. Under this perspective pores are represented by nodes and the space for the flow of fluids between them is represented by links. Pore properties such as position and size are described by fixed states in a metric space, while an affinity function is introduced to bias the attachment probabilities of links according to these properties. We perform an analytical study of the degree distributions in the soil model and show that under reasonable conditions all the model variants yield a multiscaling behavior in the connectivity degrees, leaving a empirically testable signature of heterogeneity in the topology of pore networks. We also show that the power-law scaling in the degree distribution is a robust trait of the soil model and analyze the influence of the parameters on the scaling exponents. We perform a numerical analysis of the soil model for a combination of parameters corresponding to empirical samples with different properties, and show that the simulation results exhibit a good agreement with the analytical predictions.

scholarly journals A review on analytical techniques for natural convection investigation in a heated closed enclosure: Case study

2015 ◽  
Vol 19 (3) ◽  
pp. 1077-1095 ◽  
Author(s):  
Alina Minea
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Numerical Analysis ◽  
Analytical Methods ◽  
Analytical Study ◽  
Convection Heat Transfer ◽  
Analytical Techniques ◽  
Convection Heat ◽  
Transfer Processes

The aim of this paper is to present a theoretical analysis of a few convection problems. The investigations were started from the geometry of a classic muffle manufactured furnace. During this analytical study, different methodologies have been carefully chosen in order to compare and evaluate the effects of applying different analytical methods of the convection heat transfer processes. In conclusion, even if there are available a lot of analytical methods, natural convection in enclosed enclosures can be studied correctly only with numerical analysis. Also, in this article is presented a case study on natural convection application in a closed heated enclosure.

scholarly journals A study of self-oscillation instability in varicap-based electrical networks: analytical and numerical approaches

2019 ◽  
pp. 323-336
Author(s):  
В.А. Васильченко ◽  
М.О. Корпусов ◽  
Д.В. Лукьяненко ◽  
А.А. Панин
Keyword(s):  
Differential Equation ◽  
Partial Differential Equation ◽  
Numerical Analysis ◽  
Analytical Study ◽  
Complex Coefficient ◽  
A Posteriori ◽  
Electrical Networks ◽  
Blowup Of Solutions ◽  
Oscillation Instability ◽  
Numerical Approaches

Проведено аналитическое и численное исследование разрушения решения одного нелинейного уравнения cоболевского типа, которое описывает процессы в электрических схемах на основе варикапов. Аналитическое исследование проводилось энергетическим методом. Для численного решения исходное уравнение в частных производных аппроксимировалось с помощью метода прямых системой обыкновенных дифференциальных уравнений, которая затем решалась с помощью одностадийной схемы Розенброка с комплексным коэффициентом. В основе численной диагностики разрушения решения исследуемого уравнения лежало вычисление апостериорной асимптотически точной оценки погрешности приближенного решения на последовательно сгущающихся сетках. The blowup of solutions is analytically and numerically studied for a certain Sobolevtype equation describing processes in varicapbased electrical networks. The energy method is used for the analytical study. For the numerical analysis, the original partial differential equation is approximated using a system of ordinary differential equations solved by the onestage Rosenbrock scheme with a complex coefficient. The numerical diagnostics of solutions blowup is based on a posteriori asymptotically exact error estimation on sequentially condensed grids.

Analytical study of the frequency-dependent earth conduction effects on underground power cables

2013 ◽  
Vol 7 (3) ◽  
pp. 276-287 ◽  
Author(s):  
Theofilos A. Papadopoulos ◽  
Andreas I. Chrysochos ◽  
Grigoris K. Papagiannis
Keyword(s):  
Analytical Study ◽  
Power Cables ◽  
Frequency Dependent ◽  
Underground Power Cables
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