scholarly journals Energy conserving coupling through small apertures in an infinite perfect conducting screen

2015 ◽  
Vol 13 ◽  
pp. 227-232 ◽  
Author(s):  
J. Petzold ◽  
S. Tkachenko ◽  
R. Vick
Keyword(s):  
Energy Conservation ◽  
Analytical Approach ◽  
Dipole Moments ◽  
Exciting Field ◽  
Conducting Plane ◽  
Equivalent Problem ◽  
Energy Conserving ◽  
Small Antenna ◽  
Conducting Screen

Abstract. Apertures in shielding enclosures are an important issue for determining shielding efficiencies. Various mathematical procedures and theories were employed to describe the coupling between the regions connected via an aperture in a well conducting plane. Bethe's theory describes the coupling via the equivalent problem of field excited dipole moments at the location of the aperture. This approach neglects the reaction of the dipole moments on the exciting field and therefore violates energy conservation. This work emphasizes an analytical approach for coupling between half-spaces through small apertures, inspired by the so called method of small antenna, which allows an understandable generalization of Bethe's theory.

scholarly journals Numerical Development and Evaluation of an Energy Conserving Conceptual Stochastic Climate Model

2019 ◽  
Vol 5 (1) ◽  
pp. 45-64 ◽  
Author(s):  
Federica Gugole ◽  
Christian L. E. Franzke
Keyword(s):  
Energy Conservation ◽  
Total Energy ◽  
Prediction Models ◽  
Climate Model ◽  
Empirical Orthogonal Functions ◽  
Correlated Noise ◽  
Spatial Covariance ◽  
Conservation Of Energy ◽  
Stochastic Climate Model ◽  
Energy Conserving

AbstractIn this study we aim to present the successful development of an energy conserving conceptual stochastic climate model based on the inviscid 2-layer Quasi-Geostrophic (QG) equations. The stochastic terms have been systematically derived and introduced in such away that the total energy is conserved. In this proof of concept studywe give particular emphasis to the numerical aspects of energy conservation in a highdimensional complex stochastic system andwe analyzewhat kind of assumptions regarding the noise should be considered in order to obtain physical meaningful results. Our results show that the stochastic model conserves energy to an accuracy of about 0.5% of the total energy; this level of accuracy is not affected by the introduction of the noise, but is mainly due to the level of accuracy of the deterministic discretization of the QG model. Furthermore, our results demonstrate that spatially correlated noise is necessary for the conservation of energy and the preservation of important statistical properties, while using spatially uncorrelated noise violates energy conservation and gives unphysical results. A dynamically consistent spatial covariance structure is determined through Empirical Orthogonal Functions (EOFs). We find that only a small number of EOFs is needed to get good results with respect to energy conservation, autocorrelation functions, PDFs and eddy length scale when comparing a deterministic control simulation on a 512 × 512 grid to a stochastic simulation on a 128 × 128 grid. Our stochastic approach has the potential to seamlessly be implemented in comprehensive weather and climate prediction models.

scholarly journals ENERGY-CONSERVING AND RECIPROCAL SOLUTIONS FOR HIGHER-ORDER PARABOLIC EQUATIONS

2001 ◽  
Vol 09 (01) ◽  
pp. 183-203 ◽  
Author(s):  
DMITRY MIKHIN
Keyword(s):  
Finite Difference ◽  
Energy Conservation ◽  
Difference Scheme ◽  
Numerical Solution ◽  
Finite Difference Scheme ◽  
Flow Reversal ◽  
Difference Operators ◽  
Energy Conserving ◽  
The One ◽  
Moving Media

The energy conservation law and the flow reversal theorem are valid for underwater acoustic fields. In media at rest the theorem transforms into well-known reciprocity principle. The presented parabolic equation (PE) model strictly preserves these important physical properties in the numerical solution. The new PE is obtained from the one-way wave equation by Godin12 via Padé approximation of the square root operator and generalized to the case of moving media. The PE is range-dependent and explicitly includes range derivatives of the medium parameters. Implicit finite difference scheme solves the PE written in terms of energy flux. Such formalism inherently provides simple and exact energy-conserving boundary condition at vertical interfaces. The finite-difference operators, the discreet boundary conditions, and the self-starter are derived by discretization of the differential PE. Discreet energy conservation and flow reversal theorem are rigorously proved as mathematical properties of the finite-difference scheme and confirmed by numerical modeling. Numerical solution is shown to be reciprocal with accuracy of 10–12 decimal digits, which is the accuracy of round-off errors. Energy conservation and wide-angle capabilities of the model are illustrated by comparison with two-way normal mode solutions including the ASA benchmark wedge.

A Mass and Energy Conserving Finite Element Lubrication Algorithm

1994 ◽  
Vol 116 (4) ◽  
pp. 667-671 ◽  
Author(s):  
A. Kumar ◽  
J. F. Booker
Keyword(s):  
Finite Element ◽  
Energy Conservation ◽  
Computational Effort ◽  
Lubricant Film ◽  
Cavitation Model ◽  
Energy Conserving

A previous mass-conserving finite element cavitation model is extended to include energy conservation in the lubricant film. The extension introduces no additional iteration and very little additional computational effort.

Sacrificing Environmental Control for Energy Conservation—A Consultant's Viewpoint

1978 ◽  
Vol 22 (1) ◽  
pp. 532-532 ◽  
Author(s):  
Richard B. Hayter
Keyword(s):  
Energy Conservation ◽  
Control Systems ◽  
Energy Management ◽  
Environmental Conditions ◽  
Environmental Control ◽  
Related Effect ◽  
Management Consultant ◽  
Energy Conserving ◽  
Energy Manager

An energy management consultant has a number of options available to him to conserve energy in existing or new building environmental control systems. Unfortunately, many of the options may also reduce the precision in maintaining a desired set of environmental conditions. Therefore, the energy manager must seek to maximize energy conserved yet minimuze occupant discomfort. A number of energy conserving environmental control modifications are described as well as the related effect they may have on the degree of occupant discomfort.

Thermal Property Detection and Energy-Saving Analysis of Two Groups of Hollow Blocks

2012 ◽  
Vol 487 ◽  
pp. 874-878
Author(s):  
Hui Min Li ◽  
Gang Chen ◽  
Xin Chen
Keyword(s):  
Energy Conservation ◽  
Thermal Property ◽  
Energy Saving ◽  
Building Energy ◽  
The Other ◽  
Building Energy Conservation ◽  
Energy Conserving ◽  
Save Energy ◽  
The Way

Following the increasing emphasis on building energy conservation in our country, each city issued a series of building energy-conserving standards, advises, provisions and policys one after the other, the relevant departments pay more and more attention to the wall reformation which supply a broad market to hollow blocks and many kinds of hollow blocks with different structures have spring up. In this thesis , we detective the thermal property of two different kinds of three-row-hole blocks through experiment , analyse the energy conserving index of them and the way of save energy with the experiment result .

Starvation-induced changes in metabolic rate, blood flow, and regional energy expenditure in rats

1986 ◽  
Vol 64 (9) ◽  
pp. 1252-1258 ◽  
Author(s):  
Stephanie W. Y. Ma ◽  
David O. Foster
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Energy Expenditure ◽  
Energy Conservation ◽  
Metabolic Rate ◽  
Whole Body ◽  
Tissue Blood Flow ◽  
Energy Conserving ◽  
Overnight Fasting ◽  
Quantitative Changes

Starvation results in an energy-conserving reduction in metabolic rate that has features of an adaptive response. Tissue and organ sites of this response were investigated by examining the effects of starvation for 5 d on tissue blood flow (microsphere method) and regional arteriovenous O2 differences [Formula: see text] in conscious rats resting quietly at 28 °C. Comparison was with fed and overnight-fasted animals. Whole body resting metabolic rates (MR), colonic temperatures (Tc), and tissue weights were also determined. Quantitative changes in energy expenditure (as O2 consumption) were obtained for two regions: the portal-drained viscera (PDV) and the hindquarters (HQ). Fasting overnight resulted in increased blood flow to white adipose tissue (WAT) and decreased flow to the brain, PDV, testes, and skin; however, MR, Tc, the two regional [Formula: see text], and the weights of most tissues were not significantly altered. In comparison with overnight fasting, starvation for 5 d resulted in a 13% reduction in body weight, weight loss in many tissues and organs, a 26% reduction in MR, a decline of 0.5 °C in Tc, decreased [Formula: see text] across both the PDV and HQ, reduced cardiac output, and decreased blood flow to the heart, PDV, skin, WAT, leg muscle, HQ, and the musculoskeletal body as a whole. Utilization of O2 by the PDV and HQ [Formula: see text] declined by amounts that accounted for 22 and 18%, respectively, of the reduction in MR. The reductions in cardiac output (18%) and heart blood flow (36%) indicate that the heart also made a contribution to energy conservation (roughly estimated as 5%). Overall, the data suggest that gut and muscle together accounted for two-thirds to three-quarters of the starvation-induced energy conservation.

SCATTERING FROM A HALF-LOOP ON AN INFINITE PERFECTLY CONDUCTING PLANE

1967 ◽  
Vol 45 (10) ◽  
pp. 3347-3355
Author(s):  
M. A. Plonus
Keyword(s):  
Magnetic Dipole ◽  
Incident Wave ◽  
Electric Dipole ◽  
Scattered Field ◽  
Dipole Moments ◽  
Image Theory ◽  
Conducting Plane ◽  
Wire Loop ◽  
Half Loop

Scattering from a small wire loop is derived using expressions of V. H. Weston. It is shown that the scattered field can be identified with two dipole-type scatterers, an electric and a magnetic dipole. Using image theory, scattering from a half-loop on a conducting plane is obtained. The scattered field consists of contributions of an electric dipole normal to the plane and a magnetic dipole normal to the plane of the half-loop. The equivalent scattering dipole moments are expressed in terms of the loop geometry and the orientation and polarization of the incident wave.

An Analytical Approach to the Extrusion Pressure of Bimetallic Tube

2010 ◽  
Vol 443 ◽  
pp. 87-92
Author(s):  
Guo Liang Xie ◽  
Jing Liu ◽  
Jing Tao Han ◽  
Pei Jie Yan
Keyword(s):  
Mechanical Properties ◽  
Energy Conservation ◽  
Analytical Method ◽  
Analytical Approach ◽  
Metal Flow ◽  
Extrusion Process ◽  
Extrusion Pressure ◽  
Bimetallic Tube ◽  
Good Agreement

In this paper, the extrusion process of bimetallic tubes is discussed, and the extrusion pressure is calculated based on the method of energy conservation, according to the three categories of metal flow that may occur during the process. A number of parameters, geometry of bimetallic tube, mechanical properties of material components and friction conditions, are highlighted in this analytical method. Compared with the data of TP304l/20G bimetallic tubes which were extruded at 1100-1200 °C, the calculated results show a good agreement with the industrial results, with the error less than 10 %. It also proves that the friction between the two layers play an important role in the process.

Consumer energy conservation policy An analytical approach

Energy Policy ◽  
1984 ◽  
Vol 12 (2) ◽  
pp. 201-212 ◽  
Author(s):  
Gordon H.G. McDougall ◽  
J.R.Brent Ritchie
Keyword(s):  
Energy Conservation ◽  
Analytical Approach ◽  
Conservation Policy
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