Liquid dielectric

About: Liquid dielectric is a research topic. Over the lifetime, 3702 publications have been published within this topic receiving 45150 citations.

Nanomaterials fabricated using spark erosion and other particle fabrication processes

Abstract: Methods, systems, and devices are disclosed for fabricating clean, oxidation-free nanoparticles of electrically conducting metals and alloys using spark erosion techniques. In one aspect, a method includes dispersing bulk pieces of an electrically conducting material in a dielectric fluid with mechanical vibrations within a container; generating an electric field using electrodes in the dielectric fluid using by an electric pulse, in which the electric field creates a plasma in a volume existing between the bulk pieces that locally heats the bulk pieces to form structures within the volume, the dielectric fluid quenching the structures to form nanoparticles, and filtering the nanoparticles through a screen including holes of a size allowing nanoparticles of the size or smaller to pass through the screen to a region in the container, in which the dielectric fluid inhibits oxidation of the surface of the nanoparticles.

Microwave phase shifter with liquid dielectric having metallic particles in suspension

Abstract: Microwave phase shifters and electronic beam steering antennas are described which use an electrically controllable anisotropy dielectric medium in the microwave beam path.

Viscoelasticity of a dielectric fluid in nonuniform electric fields generated by electrodes with flocked fabrics

Abstract: The rheological behavior of a dielectric fluid is studied in nonuniform electric fields which are generated by an electrode covered with flocked fabrics. Although no electrorheological (ER) effects are observed in uniform fields between metal electrodes with smooth surfaces, striking increases in viscosity and elastic response are induced by the electrode with flocked fabrics. The presence of flocked fabrics does not have a significant effect on the fluid rheology without electric fields. The ER behavior and current density are influenced by the fiber length even at a constant field strength. When a very small amount of fine particles is introduced in the electrified fluid without shear, we can see the rapid and large-scale motion of particles between the tips of fibers and plate electrode. In high DC fields, the Coulomb force acting on a free charge often gives rise to the secondary motion of fluid. The local motion of fluid in high electric fields is refereed to as electrohydrodynamic (EHD) convection. The additional energy may be required to change the periodic patterns of EHD convection by forced shear. Therefore, the ER effect demonstrated by the modification of electrode with flocked fabrics can be attributed to a combined effect of EHD convection and external shear.

Diagnosis of medium voltage XLPE cables by high voltage dielectric spectroscopy

Abstract: This paper summarize results from work on diagnosis of medium voltage (MV) XLPE cables with respect to water treeing performed at KTH, Stockholm The work, performed both in laboratory and in the field, has shown that high voltage dielectric spectroscopy is a good tool for diagnosis of MV XLPE cables and that it is able to differentiate between different stages of water tree ageing