Shields

About: Shields is a research topic. Over the lifetime, 1456 publications have been published within this topic receiving 10896 citations.

ent Analysis of Complex Configurations in Presence of Shields

Abstract: A finite element (FE) approach is presented to anal~e the electromagnetic field in free space considering the etration through shields in complex configurations. The shield region is eliminated from the FE domain and subst~tu~ed by an equivalent surface, where constraint condi~ions avoid the continuity of the tangential fields. The constraint re~ation§hips between the tangential fields on both facets of the surface are obtained by the shielding theory. ~mple~en~ation of the proposed method is presented to solve the electric field wave equation using edge elements.

Hypervelocity Impact Testing of a Metallic Glass‐Stuffed Whipple Shield

Abstract: In this work, hypervelocity impact tests up to 7 km · s−1 are used to compare the performance of Whipple shields integrated with layers of metallic glasses with a baseline target analogue of one of the shields similar to what is used on the International Space Station. The baseline target failed under the impact while the target utilizing metallic glass as a replacement for the fabric layers in the baseline passed the test. The paper postulates on the prospects of future implementation of metallic glasses as spacecraft debris shields.

Aspirating pyrometer with platinum thermocouple and radiation shields

Abstract: An aspirating or suction pyrometer for measuring hot combustion gases. A thermocouple in the pyrometer has a temperature sensitive junction formed of platinum alloys. The thermocouple junction is insulated and is encased within a platinum alloy sheath. The sheathed thermocouple is mounted within inner and outer tubular radiation shields. These shields are formed of a platinum alloy having a radiation emissivity substantially the same as the thermocouple. The shields block radiated heat from the flame and combustion chamber from being transferred to the thermocouple. The radiation shields do not themselves radiate heat to the thermocouple because the shields and thermocouple are at the same temperature and formed of substantially the same noble alloys.

Optimizing active and passive magnetic shields in induction heating by a genetic algorithm

Abstract: This paper presents a method for designing optimal passive and active shields for axisymmetric induction heaters. Such shields are needed to protect human operators and external electronic equipment from stray magnetic fields. The method uses a genetic algorithm (GA) to minimize an objective function. This function reduces the magnetic field in the target area, the power dissipation in the active and passive shields, and the influence of the shields on the heating process. The GA returns the position and height of the passive shield, the optimal current for the active shield, and the number of turns of all coils. The paper describes two optimization modes: 1) optimization of only the active shield with fixed passive shield and 2) global optimization of both active and passive shields. Several passive shields are studied: electrically conductive shields and both electrically and magnetically conductive shields. The field reduction depends on the optimization mode and the passive shield properties, but always exceeds 25 dB for combined active and passive shields. Finally, the paper compares the results of the simulations to experimental measurements.