CEM Validation-VERIFICATION AND VALIDATION OF COMPUTATIONAL ELECTROMAGNETICS SOFTWARE (original) (raw)
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CEM SOFTWARE: CHARACTERIZATION, COMPARISON, AND VALIDATION OF ELECTROMAGNETIC MODELING SOFTWARE.pdf
The continuously increasing number of electromagnetic computer models (codes) and applications thereof is one result of a rapidly expanding computing resource base of exponentially growing capability. While the growing use of computers in electromagnetics attests to the value of computer modeling for solving problems of practical interest, the proliferation of codes and results being produced increases the need for their validation with respect to both electromagnetic formulation and software implementation. But validation is perhaps the most difficult step in code development, especially for those models intended for general-purpose application where they may be used in unpredictable or inappropriate ways. A procedure or protocol for validating codes both internally, where necessary but not always sufficient checks of a valid computation can be made, and externally, where independent results are used for this purpose, is needed. Ways of comparing differing computer models with respect to their efficiency and utility to make more relevant intercode comparisons and thereby provide a basis for code selection by users having particular problems to model are also needed. These issues are discussed in this article and some proposals are presented for characterizing, comparing, and validating EM modeling codes in ways most relevant to the end user.
Validation, verification and calibration in applied computational electromagnetics
2010
Model validation, data verification, and code calibration (VV&C) in applied computational electromagnetics is discussed. The step by step VV&C procedure is given systematically through canonical scenarios and examples. Propagation over flat-Earth with linearly decreasing vertical refractivity profile, having an analytical exact solution, is taken into account as the real-life problem. The parabolic wave equation (PWE) is considered as the mathematical model. MatLab-based numerical simulators for both the split step Fourier and finite element implementations of the PWE are developed. The simulators are calibrated against analytical exact and high frequency asymptotic solutions. Problems related to the generation of reference data during accurate numerical computations are presented.
CEM-A Selective Survey of Computational Electromagnetics
The continuing growth of computing resources is changing how we think about, formulate, solve, and interpret problems. In electromagnetics, as elsewhere, computational techniques are complementing the more traditional approaches of measurement and analysis to expand vastly the breadth and depth of problems that are now quantifiable. An attempt is made to place into perspective some of the tools used in computational electromagnetics with respect to the different kinds of approaches that may be used and their computer-resource requirements, paying particular attention to numerical models based on integral and differential equations. After a brief background discussion, some of the analytical and numerical issues involved in developing a computer model are reviewed. Some practical considerations are included from the viewpoint of computer-resource requirements, followed by a discussion of some ways by which computer time might be reduced. The presentation concludes with a brief examination of validation and error checking. The emphasis throughout is on review and summarization rather than detailed exposition.
Computations have become a tool coequal with mathematics and measurements as a means of performing electromagnetic analysis and design. This is attested to by the volume of articles and meeting presentations in which computational electromagnetics (CEM) is routinely employed to address an increasing variety of problems. Yet, in spite of the substantial resources invested in CEM software over the past three decades, little real progress seems to have been made towards providing the EM engineer software tools having a functionality equivalent to that expected of experimental hardware. Furthermore, the bulk of CEM software now available is generally of limited applicability to large, complex problems because most modeling codes employ a single field propagator, or analytical form, of Maxwell's Equations. The acknowledged advantages of hybrid models, those which employ different propagators in differing regions of a problem, are relatively unexploited.
IEEE Electromagnetic Compatibility Magazine, 2017
In this paper guidelines and benchmark examples from IEEE standard and recommended practice 1597 for validation of computational electromagnetics computer modeling and simulations are applied with the aim of evaluating their practicality and consistency. Benchmark examples include a thin dipole antenna, a loop antenna, and a rectangular cavity with two apertures. In addition, a fourth example-consisting of a box-shaped monopole antenna on a finite plate-is measured and simulated. All examples are investigated by means of three different numerical techniques commonly applied by EMC engineers using two commercially available software tools and one self-developed software tool. Numerical results for input impedance, electromagnetic field values, farfield pattern, power budget, and shielding effectiveness obtained by the different techniques are compared and discussed with regard to the validation procedure outlined in IEEE standard 1597. Applicable simulation results are compared to results from closed-form equations and measurements. Observations with regard to differences between the techniques are outlined, and recommendations for a pragmatic application of IEEE standard 1597 are given.
Validating EM Data-REQUIRING QUANTITATIVE ACCURACY STATEMENTS IN EM DATA.pdf
Of all the activities associated with developing computer models for any application including computational electromagnetics (CEM), validation must be considered the most critical over the long term. Without quantitative assurance that the results produced by a model are commensurate with the needs of the intended application, there will always remain questions concerning whether analysis and design evaluations based on that model can be relied upon. Unfortunately, in contrast to the situation in years past when experimental measurements were the principle source of such data and error estimates were routinely expected to accompany them, the growth in computer-model results seems to be characterized by an almost complete lack of accuracy statements. As a means of correcting this problem, it is first proposed that some modest initial steps be taken, such as requiring error estimates to be included with all computed data published in the CEM literature. The rest of the paper provides additional background and considers aspects of model validation as a means of improving CEM overall model utility.
A Selective Survey of Computational Electromagnetics
The continuing growth of computing resources is changing how we think about, formulate, solve, and interpret problems. In electromagnetics, as elsewhere, computational techniques are complementing the more traditional approaches of measurement and analysis to expand vastly the breadth and depth of problems that are now quantifiable. An attempt is made to place into perspective some of the tools used in computational electromagnetics with respect to the different kinds of approaches that may be used and their computer-resource requirements, paying particular attention to numerical models based on integral and differential equations. After a brief background discussion, some of the analytical and numerical issues involved in developing a computer model are reviewed. Some practical considerations are included from the viewpoint of computer-resource requirements, followed by a discussion of some ways by which computer time might be reduced. The presentation concludes with a brief examination of validation and error checking. The emphasis throughout is on review and summarization rather than detailed exposition.
CEM-Computational Electromagnetics.pdf
We briefly consider here a classification of model types, the steps involved in developing a computer model , the desirable attributes of a computer model, and finally the role of approximation throughout the modeling process.