Liquid dielectric

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

Parallel cooling of heat source mounted on a heat sink by means of liquid coolant

Abstract: A module includes a cold plate. Solid-state heat sources are thermally mounted on the cold plate in a chamber defined by the cold plate and a lid. Cooling of the heat sources is enhanced by a dielectric liquid within the chamber. The liquid has a boiling point slightly below the temperatures of “hot” spots, to form small bubbles during operation, which enhance convection flow. The liquid may be a mixture of fluorocarbons of different boiling points. The liquid may contain diamond particles.

Capacitor having high temperature stability, high dielectric constant, low dielectric loss, and low leakage current

Abstract: Examples of the present invention include high electric energy density polymer film capacitors with high dielectric constant, low dielectric dissipation tangent, and low leakage current in a broad temperature range. More particularly, examples include a polymer film capacitor in which the dielectric layer comprise a copolymer of a first monomer (such as tetrafluoroethylene) and a second polar monomer. The second monomer component may be selected from vinylidene fluoride, trifluoroethylene or their mixtures, and optionally other monomers may be included to adjust the mechanical performance. The capacitors can be made by winding metallized films, plain films with metal foils, or hybrid construction where the films comprise the new compositions. The capacitors can be used in DC bus capacitors and energy storage capacitors in pulsed power systems.

Effect of material properties on reverse flow in nematic liquid crystal devices with homeotropic alignment

Abstract: Reverse flow is undesirable in liquid crystal devices with vertical alignment. The influence of the material properties on the onset of backflow is investigated for commercially available negative dielectric liquid crystals. It is shown that the threshold voltage VBF for the occurrence of backflow is an important material characteristic. This threshold is relevant for applications and a large value is desired in devices to avoid backflow while keeping a wide applicable voltage range. Accurate finite element simulation of the liquid crystal hydrodynamics allows extraction of VBF and the unknown Miesowicz coefficients ηij. The resulting values are tabulated at 20.0 °C.

Three-dimensional LBE simulations of a decay of liquid dielectrics with a solute gas into the system of gas-vapor channels under the action of strong electric fields

Abstract: The three-dimensional simulations of an anisotropic decay of binary mixtures of a dielectric liquid with solute gas in a strong electric field are carried out. The Lattice Boltzmann Equation method (LBE) is exploited for computer simulations of the evolution of such systems with the newly arising interfaces between vapor and liquid phases. The parallel implementation of the LBE algorithm is realized on a large number of cores in the GPU. For the GPU programming, the CUDA technology is used. It is important that new regions of the low-density phase appear as thin quasi-cylindrical gas-vapor channels oriented along the electric field. The gas-vapor channels expand because of the diffusion of the solute gas from the mixture, evaporation of liquid into the channels and also due to the coalescence of channels with each other. The critical values of electric field necessary for such decay of a binary mixture are considerably lower than the critical electric field for pure dielectric liquids. Hence, if we take into account a solute gas, the electric fields for which the anisotropic mechanism of streamer channels generation and growth is operated, become considerably lower. Thus, at a breakdown of dielectric liquids in a strong electric field, the anisotropic instability is possibly the key mechanism of the generation of a gas phase, inception of conducting streamer structures, their fast growth in the form of thin filamentary channels, as well as branching of streamer structures during propagation.