991 research outputs found
Luca and Mariano Rubinacci in conversation with G. Bruce Boyer
No full textMariano and Luca Rubinacci of the world-renowned House of Rubinacci discuss the Neapolitan school of tailoring with G. Bruce Boyer, menswear expert, writer, and editor, and co-curator of the Museum at FIT exhibition, Elegance in an Age of Crisis: Fashions of the 1930s. Presented by The Museum at FIT. March 26, 2014.Introduced by Patricia Mears
An analytical demonstration of coupling schemes between magnetohydrodynamic codes and eddy current codes
No full textIn order to model a magnetohydrodynamic (MHD) instability that strongly couples to external conducting structures (walls and/or coils) in a fusion device, it is often necessary to combine a MHD code solving for the plasma response, with an eddy current code computing the fields and currents of conductors. We present a rigorous proof of the coupling schemes between these two types of codes. One of the coupling schemes has been introduced and implemented in the CARMA code {[}R. Albanese, Y. Q. Liu, A. Portone, G. Rubinacci, and F. Villone, IEEE Trans. Magn. 44, 1654 (2008); A. Portone, F. Villone, Y. Q. Liu, R. Albanese, and G. Rubinacci, Plasma Phys. Controlled Fusion 50, 085004 (2008)] that couples the MHD code MARS-F {[}Y. Q. Liu, A. Bondeson, C. M. Fransson, B. Lennartson, and C. Breitholtz, Phys. Plasmas 7, 3681 (2000)] and the eddy current code CARIDDI {[}R. Albanese and G. Rubinacci, Adv. Imaging Electron Phys. 102, 1 (1998)]. While the coupling schemes are described for a general toroidal geometry, we give the analytical proof for a cylindrical plasma
Magnetostatic field computations in terms of two‐component vector potentials
No full textIn this paper the magnetostatic problem is stated in terms of two‐component electric and magnetic vector potentials. An associated numerical method, based on the adoption of edge elements, is proposed. This procedure overcomes the cancellation problems and the complexity of the interface conditions encountered by similar approaches in the presence of magnetic inhomogeneities and discontinuities of currents and magnetic fields. Copyright © 1990 John Wiley & Sons, Lt
Broad band modeling of a superconducting magnetic energy storage (SMES) coil
No full textIn this paper, we compute with accuracy the impedance parameters of a superconducting magnetic energy storage (SMES) system. We do this by using a three-dimensional integral formulation of the full set of frequency domain Maxwell's equations in the quasistatic limit. The impedance parameter allows the construction of a time domain equivalent circuit to be used for the simulation of the overall SMES system. The numerical model is based on a volume integral formulation where the unknown is the total current density J, expressed as the sum of its solenoidal and non-solenoidal components. This separation allows to avoid the ill-conditioning of the relevant stiffness matrix at low frequencies, being essential for developing a numerical model accurately working where the SMES resonances are located. The model is applied to the case of an ideal model coil consisting of an 18-layers solenoid
Eddy Current Tomography
No full textIn eddy current tomography, the conductivity profile of conductive materials is reconstructed through the inversion of eddy current data (ECT). The state of the art of imaging methods in ECT data inversion is represented by iterative methods, the drawbacks of which are their high computational cost and the risk of becoming trapped in false solutions (local minima). In this chapter, we discuss the “Monotonicity Principle Method,” a fast non-iterative approach recently developed for elliptic problems (such as electrical resistance tomography) and then extended to parabolic problems (such as eddy current tomography) and hyperbolic problems (such as microwave tomography).
This chapter discusses the main features of the Monotonicity Principle in eddy current testing. Specifically, section “Monotonicity Principle for Eddy Current Imaging in the Large Skin-Depth Regime” discusses the Monotonicity Principle for eddy current testing in the “large” skin-depth regime, then section “Imaging Method” introduces the related imaging method (Monotonicity Principle Imaging Method, MPIM), and section “Monotonicity Principle for Eddy Currents in Other Settings” introduces other setting where Monotonicity Principle holds and MPIM can be applied
Elegance in an Age of Crisis: Part 2 His
No full textA video exploring key themes of “Elegance in an Age of Crisis” an exhibition about 1930s style at The Museum at FIT February 7 to April 19, 2014. Part 2 features menswear writer G. Bruce Boyer, Savile Row tailor Stephen Hitchcock, Luca Rubinacci of London House, and Massimiliano Attolini of Cesare Attolini discussing men’s style of the era. Shot and edited for MFIT by Andrew Yamato
On the computation of the disruption forces in tokamaks
No full textThe currents and forces induced in the tokamak vacuum vessel (wall) during the disruption are calculated for different values of wall resistivity. Several consequences and new developments are derived from the general result that the global disruption force acting on the perfectly conducting wall must be exactly opposite to the similar force acting on the plasma, which is inherently small in tokamaks. This theoretical prediction is tested and confirmed here for the ITER tokamak with disruption modelled as the fast thermal quench followed by slower current quench that develops into the vertical displacement event. The plasma is simulated by the evolutionary equilibrium code CarMa0NL. One of the results is that the computed integral force on a perfectly conducting wall is zero at each instant during a disruption. This in turn highlights the importance of having good models for the plasma (in which the equilibrium constraint is explicitly imposed) and for the structures (able to correctly describe the induced currents and the resistive effects). The dependence of the disruption force on the magnetic field penetration through the wall is demonstrated. Also the concept of a disruption force damper is proposed, able to 'absorb' a significant part of the force that would arise on a resistive wall during a disruption
Power-law characteristic for 3-D macroscopic modeling of superconductors via an integral formulation
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