scholarly journals A lowpass filter based on a 2d microstrip electromagnetic crystal

2019 ◽  
Vol 485 (1) ◽  
pp. 27-32
Author(s):  
B. A. Belyaev ◽  
S. A. Khodenkov ◽  
R. G. Galeev ◽  
V. F. Shabanov

A new construction of a lowpass filter was developed based on a two-dimensional microstrip electromagnetic crystal, which had a steeper slope of the frequency response as compared to a filter consisting of a one-dimensional microstrip electromagnetic crystal. The investigated lowpass filter construction is characterized by a high workability and ease of manufacturing. Electrodynamic numerical simulation of the 3D model of the considered microstrip structure agrees well with the experiment, which allows conducting parametric synthesis of devices with the required properties using a personal computer.

2020 ◽  
Vol 37 (8) ◽  
pp. 2913-2938
Author(s):  
Rajul Garg ◽  
Harishchandra Thakur ◽  
Brajesh Tripathi

Purpose The study aims to highlight the behaviour of one-dimensional and two-dimensional fin models under the natural room conditions, considering the different values of dimensionless Biot number (Bi). The effect of convection and radiation on the heat transfer process has also been demonstrated using the meshless local Petrov–Galerkin (MLPG) approach. Design/methodology/approach It is true that MLPG method is time-consuming and expensive in terms of man-hours, as it is in the developing stage, but with the advent of computationally fast new-generation computers, there is a big possibility of the development of MLPG software, which will not only reduce the computational time and cost but also enhance the accuracy and precision in the results. Bi values of 0.01 and 0.10 have been taken for the experimental investigation of one-dimensional and two-dimensional rectangular fin models. The numerical simulation results obtained by the analytical method, benchmark numerical method and the MLPG method for both the models have been compared with that of the experimental investigation results for validation and found to be in good agreement. Performance of the fin has also been demonstrated. Findings The experimental and numerical investigations have been conducted for one-dimensional and two-dimensional linear and nonlinear fin models of rectangular shape. MLPG is used as a potential numerical method. Effect of radiation is also, implemented successfully. Results are found to be in good agreement with analytical solution, when one-dimensional steady problem is solved; however, two-dimensional results obtained by the MLPG method are compared with that of the finite element method and found that the proposed method is as accurate as the established method. It is also found that for higher Bi, the one-dimensional model is not appropriate, as it does not demonstrate the appreciated error; hence, a two-dimensional model is required to predict the performance of a fin. Radiative fin illustrates more heat transfer than the pure convective fin. The performance parameters show that as the Bi increases, the performance of fin decreases because of high thermal resistance. Research limitations/implications Though, best of the efforts have been put to showcase the behaviour of one-dimensional and two-dimensional fins under nonlinear conditions, at different Bi values, yet lot more is to be demonstrated. Nonlinearity, in the present paper, is exhibited by using the thermal and material properties as the function of temperature, but can be further demonstrated with their dependency on the area. Additionally, this paper can be made more elaborative by extending the research for transient problems, with different fin profiles. Natural convection model is adopted in the present study but it can also be studied by using forced convection model. Practical implications Fins are the most commonly used medium to enhance heat transfer from a hot primary surface. Heat transfer in its natural condition is nonlinear and hence been demonstrated. The outcome is practically viable, as it is applicable at large to the broad areas like automobile, aerospace and electronic and electrical devices. Originality/value As per the literature survey, lot of work has been done on fins using different numerical methods; but to the best of authors’ knowledge, this study is first in the area of nonlinear heat transfer of fins using dimensionless Bi by the truly meshfree MLPG method.


Author(s):  
В. Браннер ◽  
Д.А. Калачев

Подбор оборудования для механической очистки сточных вод является важным этапом при реконструкции или новом строительстве очистных сооружений, который определяет их эффективность и надежность с точки зрения технологии и эксплуатации. Приведены примеры распространенных на данный момент технических решений по конструкции фильтрующего полотна решеток для механической очистки сточных вод. Дано сравнение эффективности данных решений. На основе исследования очистных сооружений в Германии представлено сравнение эффективности задержания отбросов в зависимости от применяемого ранга фильтрации: двумерной (перфорация) и одномерной (прозор). The selection of equipment for mechanical wastewater treatment is an important stage in the reconstruction or new construction of the treatment facilities that determines their efficiency and reliability in terms of the technology and operation. The examples of the currently widespread technical solutions for designing filtering cloth of the screens for mechanical wastewater treatment are given. The effectiveness of these solutions is compared. On the basis of studying wastewater treatment facilities in Germany, a comparison of the debris retention efficiency depending on the applied filtration grade, i. e., two-dimensional (perforation) and one-dimensional (bar spacing) is presented.


2012 ◽  
Vol 192 ◽  
pp. 190-195
Author(s):  
Jian Hua Zhang ◽  
Kun Hu ◽  
Yi Fan Xu

The section mutation of a pipe affects the interior flow field seriously. Numerical simulation of the two-dimensional steady gas flow field of two types of section mutation pipe was processed. By comparing it with equivalent section pipe’s interior flow field, the effects of section mutation of pipe on pressure distributing and velocity distributing were analyzed. The results are commendably consistent with the theories of one-dimensional adiabatic frictional pipe flow. Ensuring the section of the compressed gas pipe to be coherent and using the bell and spigot joint if necessary are presented.


2000 ◽  
Vol 11 (07) ◽  
pp. 1321-1346 ◽  
Author(s):  
ANDREW ADAMATZKY

In collision-based computing, quanta of information are represented by autonomous mobile signals. The signals travel in a uniform architectureless medium. They collide to each other. Assuming the presence or abscence of a signal represent truth or falsity values of logical variable, we can consider logical functions are calculated at the sites of signals' collision. Physically, the signals are localized compact disturbances of medium's characteristics. In this paper, we extensively exploit results published in Refs. 1–7. We consider three types of localizations: breathers in one-dimensional arrays of DNA molecules, excitons and groups of antialigned dipoles in two-dimensional arrays of Scheibe aggregates and microtubules respectively. Several forms of logical gates are extracted from published results on numerical simulation of breathers and excitons. In cellular automata models, we study interactions of the localizations with each other. We show what kinds of logical gates can be realized in such interactions. Parallels between physical and discrete automata models are provided.


Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1728 ◽  
Author(s):  
Xiao-Ting ◽  
Zhi-Xin ◽  
Hong-Xia ◽  
Jun-Yi

The existing studies indicate polymers will present obviously different properties in tension and compression (bimodular effect) which is generally ignored because of the complexity of the analysis. In this study, a functionally graded piezoelectric cantilever beam with bimodular effect was investigated via analytical and numerical methods, respectively, in which a one-dimensional theoretical solution was derived by neglecting some unimportant factors and a two-dimensional numerical simulation was performed based on the model of tension-compression subarea. A full comparison was made to show the rationality of one-dimensional theoretical solution and two-dimensional numerical simulation. The result indicates that the layered model of tension-compression subarea also makes it possible to use numerical technique to simulate the problem of functionally graded piezoelectric cantilever beam with bimodular effect. Besides, the modulus of elasticity E* and the bending stiffness D* proposed in the one-dimensional problem may succinctly describe the piezoelectric effect on the classical mechanical problem without electromechanical coupling, which shows the advantages of one-dimensional solution in engineering applications, especially in the analysis and design of energy harvesting/sensing/actuating devices made of piezoelectric polymers whose bimodular effect is relatively obvious.


1966 ◽  
Vol 25 ◽  
pp. 46-48 ◽  
Author(s):  
M. Lecar

“Dynamical mixing”, i.e. relaxation of a stellar phase space distribution through interaction with the mean gravitational field, is numerically investigated for a one-dimensional self-gravitating stellar gas. Qualitative results are presented in the form of a motion picture of the flow of phase points (representing homogeneous slabs of stars) in two-dimensional phase space.


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