The Experts below are selected from a list of 231 Experts worldwide ranked by ideXlab platform

John R. Bowler - One of the best experts on this subject based on the ideXlab platform.

  • Eddy-Current Coil Interaction With A Perfectly Conducting Wedge of Arbitrary Angle
    Research in Nondestructive Evaluation, 2014
    Co-Authors: C. P. Trampel, John R. Bowler
    Abstract:

    In this article, a closed-form expression for the impedance of a tangential eddy-Current Coil in the presence of an infinite conducting wedge of arbitrary angle is derived. The truncated eigenfunction expansion (TREE) solution given here is valid in the quasi-static frequency regime. The theory was validated via comparison to an independent analytical expression for the impedance change of a horizontal Coil over a conducting half-space due to Burke. We present results for three geometries: a conducting quarter-space, a conducting wedge of angle 225 degrees, and a semi-infinite conducting sheet. Our theory predicts a measurable change in the tangent Coil reactance in the presence of all three geometries.

  • Interaction of an eddy-Current Coil with a right-angled conductive wedge
    2010
    Co-Authors: Theodoros Theodoulidis, John R. Bowler
    Abstract:

    A fundamental problem in eddy-Current nondestructive evaluation is one of finding the quasi-static electromagnetic field of a cylindrical Coil in the vicinity of the edge of a metal block. Although the field can be calculated numerically, an effective analytical approach can potentially provide a better understanding of the edge fields and form the basis of a procedure for solving a whole class of related edge problems including edge structures that contain corner cracks. One can represent the metal block as a conductive quarter space in an unbounded region. However, it has been found that the analysis is more straightforward if the problem domain is truncated in two dimensions. With the domain boundaries far from both the Coil and the corner, the truncation has a negligible effect on the solution near the edge but the field calculation becomes much easier. A double Fourier series representation of the field is used, as in the case of a rectangular waveguide problem. The field in the conductor is then matched at the interfaces with that in air to determine the expansion coefficients that are used to represent the field in different parts of the domain. In this way we have derived expressions for the magnetic field, the induced eddy-Current density and the Coil impedance at arbitrary position and orientation of the Coil.

  • Eddy Current Coil interaction with a right-angled conductive wedge
    Proceedings of the Royal Society A: Mathematical Physical and Engineering Sciences, 2005
    Co-Authors: Theodoros Theodoulidis, John R. Bowler
    Abstract:

    The time-harmonic electromagnetic field in an electrically conductive right-angled wedge due to an inductive excitation by circular Coil in air has been calculated. Using a formulation in Cartesian coordinates, the problem domain is truncated in a dimension whose axis is normal to a wedge face, and an approximate series solution found using elementary functions satisfying Maxwell’s equations in the quasi-static limit. The Coil impedance variation with position and frequency is calculated and compared with measurements made on a Coil near the edge of a large aluminium block which approximates the effect of a conductive quarter-space. The comparison between theory and experiment shows very close agreement.

Theodoros Theodoulidis - One of the best experts on this subject based on the ideXlab platform.

  • Interaction of an eddy-Current Coil with a right-angled conductive wedge
    2010
    Co-Authors: Theodoros Theodoulidis, John R. Bowler
    Abstract:

    A fundamental problem in eddy-Current nondestructive evaluation is one of finding the quasi-static electromagnetic field of a cylindrical Coil in the vicinity of the edge of a metal block. Although the field can be calculated numerically, an effective analytical approach can potentially provide a better understanding of the edge fields and form the basis of a procedure for solving a whole class of related edge problems including edge structures that contain corner cracks. One can represent the metal block as a conductive quarter space in an unbounded region. However, it has been found that the analysis is more straightforward if the problem domain is truncated in two dimensions. With the domain boundaries far from both the Coil and the corner, the truncation has a negligible effect on the solution near the edge but the field calculation becomes much easier. A double Fourier series representation of the field is used, as in the case of a rectangular waveguide problem. The field in the conductor is then matched at the interfaces with that in air to determine the expansion coefficients that are used to represent the field in different parts of the domain. In this way we have derived expressions for the magnetic field, the induced eddy-Current density and the Coil impedance at arbitrary position and orientation of the Coil.

  • Eddy Current Coil interaction with a right-angled conductive wedge
    Proceedings of the Royal Society A: Mathematical Physical and Engineering Sciences, 2005
    Co-Authors: Theodoros Theodoulidis, John R. Bowler
    Abstract:

    The time-harmonic electromagnetic field in an electrically conductive right-angled wedge due to an inductive excitation by circular Coil in air has been calculated. Using a formulation in Cartesian coordinates, the problem domain is truncated in a dimension whose axis is normal to a wedge face, and an approximate series solution found using elementary functions satisfying Maxwell’s equations in the quasi-static limit. The Coil impedance variation with position and frequency is calculated and compared with measurements made on a Coil near the edge of a large aluminium block which approximates the effect of a conductive quarter-space. The comparison between theory and experiment shows very close agreement.

  • Series expansions in eddy Current nondestructive evaluation models
    Journal of Materials Processing Technology, 2004
    Co-Authors: Theodoros Theodoulidis, E.e. Kriezis
    Abstract:

    Abstract The well-established Dodd and Deeds models, that are widely used in eddy Current nondestructive evaluation (NDE) and have served the industry for three decades, are being reformulated. Integral expressions for the electromagnetic field and the impedance of the eddy Current Coil are replaced by series expansions. As a result, computation time is considerably reduced, convergence is better controlled and computer implementation is greatly simplified. The analysis is performed for a Coil over a conducting half-space and a Coil inside a borehole with a conducting wall.

W.r. Jong - One of the best experts on this subject based on the ideXlab platform.

  • SIMULATIONS AND VERIFICATIONS OF INDUCTION HEATING ON A MOLD PLATE
    International Communications in Heat and Mass Transfer, 2004
    Co-Authors: Shia-chung Chen, H.s. Peng, Jen-an Chang, W.r. Jong
    Abstract:

    In this study, electromagnetic induction heating is developed to achieve a rapid mold surface heating. Both a circular Coil and a rectangular Coil of single turn were properly designed for induction heating experiments on a flat steel mold plate. For heating efficiency comparison, the second circular Coil of the same length as rectangular Coil and multiple turn Coil of rectangular shape in rectangular form were also utilized. Mold plate surface temperature distribution during induction heating process was measured using infrared thermal image system. Simulation technology was also developed by integration of both thermal and electromagnetic analysis modules of ANSYS. Coil Current, Coil to plate distance and heating time were varied for both experiments and simulations. The capability and accuracy of simulations on the induction heating were verified via experiments. The simulated temperature distributions show reasonable agreement with measured results. In addition, the multiple-turn Coil provides better heating efficiency as well as more uniformity in temperature distribution of the heated object.

Yunseok Kim - One of the best experts on this subject based on the ideXlab platform.

  • Probing of multiple magnetic responses in magnetic inductors using atomic force microscopy
    Scientific Reports, 2016
    Co-Authors: Seongjae Park, Hosung Seo, Daehee Seol, Young-hwan Yoon, Mi Yang Kim, Yunseok Kim
    Abstract:

    Even though nanoscale analysis of magnetic properties is of significant interest, probing methods are relatively less developed compared to the significance of the technique, which has multiple potential applications. Here, we demonstrate an approach for probing various magnetic properties associated with eddy Current, Coil Current and magnetic domains in magnetic inductors using multidimensional magnetic force microscopy (MMFM). The MMFM images provide combined magnetic responses from the three different origins, however, each contribution to the MMFM response can be differentiated through analysis based on the bias dependence of the response. In particular, the bias dependent MMFM images show locally different eddy Current behavior with values dependent on the type of materials that comprise the MI. This approach for probing magnetic responses can be further extended to the analysis of local physical features.

E.e. Kriezis - One of the best experts on this subject based on the ideXlab platform.

  • Series expansions in eddy Current nondestructive evaluation models
    Journal of Materials Processing Technology, 2004
    Co-Authors: Theodoros Theodoulidis, E.e. Kriezis
    Abstract:

    Abstract The well-established Dodd and Deeds models, that are widely used in eddy Current nondestructive evaluation (NDE) and have served the industry for three decades, are being reformulated. Integral expressions for the electromagnetic field and the impedance of the eddy Current Coil are replaced by series expansions. As a result, computation time is considerably reduced, convergence is better controlled and computer implementation is greatly simplified. The analysis is performed for a Coil over a conducting half-space and a Coil inside a borehole with a conducting wall.