Electromagnetic Pressure Research Articles

Single Harmonic Black Holes

In this New Theory a “Single Harmonic Black Hole” (SHBH) has been considered to be the Gravitational-Electromagnetic Confinement of a Single Harmonic Electromagnetic Field Configuration in which a perfect equilibrium exists between the outward directed electromagnetic radiation pressure and the inward directed Electromagnetic-Gravitational Interaction force densities. This frequency transformation is possible because of the combined Lorentz / Doppler-Effect transformation during the collapse (contraction) of the radiation when the Gravitational Electromagnetic Confinement has been formed (Implosion of Visible Light). Within the scope of this article “Single Harmonic Black Hole” (SHBH) is considered to be any kind of 3-dimensional confined Single Harmonic Electromagnetic Energy. The inner structure of a “SHBH” has been based on a 3-dimensional isotropic equilibrium within the electromagnetic field configuration. This new theory will explain how electromagnetic fields (wave packages) demonstrate inertia, mass and momentum and which forces keep the wave packages together in a way that they can be measured like particles with their own specific mass and momentum. To understand what electromagnetic inertia and the corresponding electromagnetic mass, spin and electric charge is and how the anisotropy of electromagnetic mass, spin and electric charge can be explained and how it has to be defined, a New Theory about “Electromagnetic-Gravitational Interaction” has been developed. The “New Theory” has been based on the fundamental principle of “Perfect Equilibrium within the Universe” which has already been expressed by Newton’s three equations published in 1687 in “Philosophiae Naturalis Principia Mathematica. Newton’s Equations in 3 dimensions will be published in this article in an extension into 4 dimensions. Newton’s 4-dimensional law in the 3 spatial dimensions results in an improved version of the classical Maxwell Equations and Newton’s law in the 4th dimension (time) results in the quantum mechanical Schrödinger wave equation (at non-relativistic velocities) and the relativistic Dirac equation.

Comparison between ionospheric disturbances caused by barium and cesium

After being released in the ionosphere, alkali-metal atoms will be rapidly photoionized by solar UV, producing positive ions and electrons, and forming artificial plasma cloud. Based on a three-dimensional two-species fluid model, considering both the loss of barium atoms due to photoionization and oxidation and the influence of horizontal wind field in the release region, the spatial-temporal evolution of the artificial plasma cloud is discussed. By taking into account the electromagnetic field force, pressure gradient, particle collisions and ion inertia, the ionospheric disturbance effects caused by barium and cesium are compared with each other. The simulation results show that the alkali metal rapidly expands after being released in the ionosphere, and the generated plasma cloud gradually forms an ellipsoidal structure from the inside to the outside under the constraint of magnetic field with considering no wind. Meanwhile, the expanded plasma cloud pushes away the background oxygen ions, forming an oxygen ion density hole in the release center and two symmetrical density bumps on both sides. In the absence of neutral wind, the plasma cloud is dominated by the movement along magnetic field, while considering the background neutral wind, the plasma cloud and background disturbance area will move along the direction of wind, so that the density gradient of plasma cloud becomes steepening on the upwind side. Although the movement of ion cloud across the magnetic field is constrained, the neutrals can pass through the magnetic field freely, so the ion cloud and neutral cloud will separate from each other slowly. Also, the presence of horizontal wind field will make a greater disturbance to the background oxygen ion. By comparing the simulation results of barium and cesium we can see that, qualitatively, the expansion characteristics of Cs<sup>+</sup> and Ba<sup>+</sup> as well as their effects on the background O<sup>+</sup> are similar. Due to the small diffusion coefficient of cesium, the barium cloud expands more rapidly and the coverage area of Ba<sup>+</sup> cloud is wider. Because of the large photoionization rate of cesium, the ionization yield of cesium is higher than that of barium when the same mass is released. In addition, the snowplow effect of Cs<sup>+</sup> is stronger than that of Ba<sup>+</sup>, and the oxygen ion density holes and bumps caused by Cs<sup>+</sup> are also larger.

THE STUDY OF ELECTROMAGNETIC SITUATION AT THE CIVIL AVIATION AIRPORTS AND FORMATION OF IMPROVEMENT MEASURES

The research has demonstrated that one of the physical factors of anthropogenic origin, generated by stationary aerodrome objects, is the broad-spectrum electromagnetic fields. They are created due to the operation of outdated radio equipment intended for aircraft maintenance, long service life, and lack of modern navigation instruments. The purpose of the work is to develop the recommendations for the definition of sanitary protection zones and their maintenance at the regulatory level, on the basis of field measurements of the electromagnetic fields intensity levels at the territory of civil aviation facilities. The analysis of field measurements of the electromagnetic levels fields parameters, performed with the help of calibrated voltage meter of electric and magnetic fields P3-31 in accordance with the instruction manual, at the territory of the Odessa International Airport has been carried out. The maximum measurement error did not exceed 2.7 dB. The deviations of terminological and even methodological character in the current standards for electromagnetic safety of Ukraine have been revealed. It is established that the methods of calculating the integral electromagnetic pressure have to be specified, provided that different sources influence the electromagnetic environment. The unit of measurement of the parameters of electric, magnetic and electromagnetic fields must be specified and amended, taking into account the available and perspective list of measuring equipment. Recommendations for the establishment of sanitary protection zones have been developed. It is proved that the existing residential area is out of the boundaries of the sanitary protection zones and zones of construction restriction for the sources of electromagnetic energy radiation at the territory of Odessa airport. The general recommendations for the improvement of electromagnetic environment at the territories of civil aviation aerodrome and its maintenance at the standart level are substantiated.

Design of a Test Section to Analyze Magneto-Convection Effects in WCLL Blankets

The water-cooled lead lithium (WCLL) blanket is one of the European concepts for a Demonstration nuclear fusion reactor (DEMO). The spatial distribution of the water-cooling pipes inside the liquid metal blanket breeder zone is a critical issue since efficient heat removal from the liquid metal has to be ensured, avoiding local hot spots in the fluid or in blanket walls. Convective motion, driven by density gradients due to volumetric heat sources in the liquid breeder and heat removal by cooling pipes, is affected by magnetohydrodynamic interactions of the electrically conducting lead lithium with the external magnetic field. For the recent complex design of the DEMO WCLL blanket, prediction of the liquid metal flow is quite difficult. Preliminary numerical and experimental studies are necessary to determine the flow distribution resulting from the combined interaction of electromagnetic forces, buoyancy, and pressure. A test section based on a simplified model geometry supported by preliminary numerical simulations has been designed for experiments in the MEKKA laboratory at the Karlsruhe Institute of Technology and is presented in this paper.

Influence of Contacting Schemes on Electromagnetic Force and Current Density Distribution in Armature

The current density and electromagnetic force distribution of the armature directly affect the performance of electromagnetic railgun. In this paper, the electromagnetic thrust, electromagnetic pressure, and current density of the C-shaped armature and H-shaped armature are calculated, respectively, by the finite-element method under different Armature–rail contact modes (different contact areas and positions), and the calculation results under different contact modes are compared. The calculation results show that the maximum current density of the armature head is independent of the contact mode, and the position of the maximum current density of the armature tail moves with the advance of the contact position. The separation of the rear part of the armature tail and rail will result in a sharp decrease in electromagnetic pressure, so the armature tail and rail need to maintain contact to ensure a stable current transfer. At the same time, only the head and the rear part of the armature tail are in contact with the rail, the electrical performance of the armature in complete contact with the rail can be achieved. Therefore, the armature adopts the structural design scheme of interference at both ends, which is more conducive to electromagnetic emission and greatly reduces the difficulty of the armature structural design.

Simulation of the Winding Angles’ Influence on the Dynamic Strength and Stiffness of Filament Wound Composite Barrel for Railgun

Based on the orthotropic composite cylindrical shell theory, the radial displacement in composite housing of railgun barrel is calculated through using the calculation principle of 3-D effective elastic moduli of composite laminate. Then, the effect of winding angles on the radial stiffness of barrel is theoretically forecast with the radial displacement as the measure index. And, a 3-D nonlinear transient finite-element model based on the damage mechanics theory and multilayered solid element is established for the filament wound composite barrel of railgun under moving electromagnetic pressure. It is used to simulate the dynamic responses and the initiation and development of damage for the railgun barrel. The effects of winding angles on the radial stiffness and dynamic strength of the railgun barrel are also analyzed with the model. Simulation results reveal that the influence trend of winding angles on the radial stiffness of barrel is close to the theoretical prediction result. In addition, the plastic deformation in rail and damage in filament wound composite housing increase as the winding angles become smaller. It means that the strength performance of filament wound composite barrel for railgun degrades basically with the winding angles decreasing.

A Study on Cooling Method for Induced Heat in Processing of Metal Thin Plate under Electromagnetic Pressure

A Study on Cooling Method for Induced Heat in Processing of Metal Thin Plate under Electromagnetic Pressure

Manufacturing Design Assessment of the Welded In-Wall Shield Rib for ITER Vacuum Vessel

Between inner and outer shells of vacuum vessel, numerous in-wall shielding (IWS) blocks are installed to provide neutron shielding. Uniquely, the IWS ribs in sector 1 and 6 are manufactured by welding and its manufacturing design shall be secured for not only manufacturability but safety point of views. For the design of IWS ribs, complex loads for multiple directional electromagnetic force, coolant pressure, and earthquake shall be considered simultaneously. Moreover, in-service inspection (ISI) is impossible after commissioning ITER, and therefore, proper design assessment procedure should be applied with reasonable conservatism. In this paper, an approach for manufacturing design of welded IWS ribs is proposed. On the basis of that approach, four representative models are screened by geometric factors and load magnitude. Under the most conservative loads among multiple loading conditions, structural safety of each representative models is verified with RCC-MR. The deviation requests for this assessment were approved to IO and ANB. This approach and results could be used as a reference for the design of vacuum vessel components, which is impossible for ISI.

A Novel Concept of Electromagnetic Pressure Sensor based on Impedance Variation for Pneumatic Applications

The core concept of the proposed sensor relies on the architecture of a new type of microscale electromagnetic actuator, previously developed and tested. Previous studies were focus on conceptual design, modelling and simulation and application as an actuator for static and dynamic purposes. Upon presenting the device functioning principle and design, the authors propose a new application of this device, as a detection element, due to its electrodynamic behavior that allows the correlation of displacements and deformations with the variation of the device coil inductance. This dependency could also be used as a feedback information, allowing a closed loop control without an aditional sensorial element. A series of numerical models have been developed and computed in order to test the sensorial properties of the device and to describe the functioning principle as a detection element. The models have been computed using two materials for the sensor’s mobile element, to test if the manufacturing costs can be lowered by using a material without magnetic properties and the conclusions of the studies have also been drawn. Once the sensor behavior and the structural materials have been concluded, a sensor model has been developed and studied using FEM. Further on, one of the sensor constructive parameters has been varied in relation to the desired measuring range and the future research directions have been drawn.

Cavity optomechanics of topological spin textures in magnetic insulators

Collective dynamics of topological magnetic textures can be thought of as a massive particle moving in a magnetic pinning potential. We demonstrate that inside a cavity resonator this effective mechanical system can feel the electromagnetic radiation pressure from cavity photons through the magneto-optical inverse Faraday and Cotton-Mouton effects. We estimate values for the effective parameters of the optomechanical coupling for two spin textures -- a Bloch domain wall and a chiral magnetic soliton lattice. The soliton lattice has magnetic chirality, so that in circularly polarized light it behaves like a chiral particle with the sign of the optomechanical coupling determined by the helicity of the light and chirality of the lattice. Most interestingly, we find a level attraction regime for the soliton lattice, which is tunable through an applied magnetic field.

Dynamics Response of Filament-Wound Composite Barrel for Rail Gun With Acceleration Load

Based on Love’s shell theory, the critical velocity of a flexural wave in the composite housing of rail-gun barrel is calculated through using the calculation principle of 3-D effective elastic moduli of composite laminate. The result is close to the one predicted by the finite-element method. A 3-D nonlinear transient finite-element model based on the damage mechanics theory and multilayered solid element is established for the filament-wound composite barrel of rail gun under moving electromagnetic pressure. It is used to analyze the dynamic responses and the initiation and development of damage for the rail-gun barrel from the viewpoint of propagation of stress wave. Simulation results reveal that some physical quantities in composite housing for rail-gun barrel, such as stress and displacement, are enlarged obviously with the moving velocity of electromagnetic pressure near the critical velocity of composite housing for rail-gun barrel. Because of the actions of stress waves in barrel, such as reflection, matrix failure occurs first on some axisymmetric planes of composite housing.

Reconnecting reconnection with its current roots

The review by Jack Zirker and Oddbjørn Engvold (Physics Today, August 2017, page 36) of recent coronal research makes extensive use of the concept of field lines—in particular, magnetic reconnection. But like the analogous streamlines in fluids, magnetic field lines are not physical entities. They are just a convenient way of visualizing the structure and behavior of magnetic fields. To convince yourself of this, think of the familiar pattern of field lines connecting the poles of a bar magnet. How many lines are there?It follows that field-line reconnection itself is not a physical phenomenon and cannot cause either coronal heating or the propulsion of plasma in coronal mass ejection events. Such coronal phenomena result from dynamical processes involving electromagnetic fields, currents, and pressures, which are physical. Reconnection merely describes the way the magnetic field topology changes.As mentioned in the article, reconnection events are associated with thin current sheets, which are related to the magnetic field by Ampere’s law. Their evolution is fundamental to understanding coronal phenomena. Eric Priest and Terry Forbes (Zirker and Engvold’s reference 3) note that James Dungey, the originator of the reconnection model, “found that small perturbations in the vicinity of the null point lead to the explosive formation of a current sheet. Near the null point, plasma motions induced by a small current perturbation cause the current to grow, and this current further enhances the plasma motions resulting in a positive feedback.”11. E. Priest, T. Forbes, Magnetic Reconnection: MHD Theory and Applications, Cambridge U. Press (2000), p. 8. Focusing on the role that the currents play in reconnection would make for a clearer understanding.ReferenceSection:ChooseTop of pageReference <<1. E. Priest, T. Forbes, Magnetic Reconnection: MHD Theory and Applications, Cambridge U. Press (2000), p. 8. Google ScholarCrossref© 2018 American Institute of Physics.

Numerical analysis for electromagnetic field influence on heat transfer behaviors in cold crucible used for directional solidification

Cold crucible directional solidification (CCDS) is the technique that the materials in the segmented water-cooled crucible are induction heated and heat transfer controlled by electromagnetic field for directional solidifying crystals without contamination. In order to control crystal growth by the CCDS efficiently, mathematical analysis of heat transfer during the CCDS process is presented by means of a combined electromagnetic, fluid and thermal model. A 3-D model is established and verified to investigate the characteristics of heat transfer in the melt, which considers the coupled effects of the shaped melt and the electromagnetically driven flow on the temperature field and the shape of solid–liquid (S/L) interface. The shaped melt by electromagnetic pressure along with the induction heat in the skin layer reduce and compensate the radial heat loss, which could decrease the radial temperature gradient in the melt with increasing input powers. A vigorous three-dimensional melt flow consisting of meridional flow and azimuthal flow is induced in the melt, which improves the uniformity of the temperature field and decreases the deflection of S/L interface in the center of melt. The solidification front changes from ‘W’ shape to planar when the power reaches 39 kW. Based on the above results and analysis, TiAl alloys are successfully directionally solidified by the CCDS method with planar S/L interface, and the growth direction of columnar crystals are nearly paralleled.

A versatile split Hopkinson pressure bar using electromagnetic loading

This paper presents a novel electromagnetic split Hopkinson pressure bar (ESHPB), which employs the electromagnetic energy conversion technique of LC circuit to generate directly the incident stress pulse.Such a versatile technique can generate easily compressive as well as tensile incident pulses. The duration and amplitude of the incident pulse could be controlled by adjusting the capacitance and charging voltage in the LC circuit. Therefore, compressive or tensile high strain-rate tests can easily be performed using the present apparatus by simply choosing the compression bars or tension bars.The primitive shape of generated stress pulse is a half-sine function, which is well suited for testing brittle materials and soft rubber-like materials in order to reach a rather constant strain rate. Meanwhile, for the tests of metals, a pulse shaper can be used to reach a rather classical trapezoidal pulse similar to that of the classical pressure bar tests. Furthermore, it is also possible to modify the stress pulse by shaping the discharge current using a specially designed active coil array and a sequential switch.Finally, a number of different materials were tested in compression and tension using this electromagnetic split Hopkinson bar system. The same materials were also tested using the traditional split Hopkinson bars. It turns out that the results obtained by the present device are consistent with those by the traditional split Hopkinson bars.Compared with traditional pulse generation techniques by the impact of a projectile or by a sudden release of a pre-stressed section, the proposed electromagnetic energy conversion technique can be accurately triggered within several microseconds. It is, therefore, a good candidate to supply the symmetrical and synchronous loads in bidirectional or biaxial split Hopkinson bar systems in the future.

Direct Data-Driven Control of Cavity Tuners in Particle Accelerators

X-Ray Free Electron Lasers (XFELs) are the next generation of X-rays sources delivering dramatical improvements over synchrotron radiation in terms of brilliance, pulse length and coherence. While obtaining such X-ray radiations, the high gradients of the accelerating electromagnetic field, external vibrations and pressure fluctuations may cause deformations of the cavities where the electrons are accelerated. This lowers the efficiency of the linear accelerator (linac) and degrades the beam quality. To contrast this phenomenon, known as "detuning", suitable mechanical compensators of cavity deformations are needed. In this paper, we propose a direct data-driven approach for the synthesis of such systems, as an alternative to the on-line iterative methods currently in use. The effectiveness of the proposed approach is shown on a complex linac simulator.

Analysis of the Electromagnetic Impulse Technology for joining of Aluminium tube to coated Steel rod.

Automotive and aerospace industries are continuously focusing on the improved lightweight hybrid structures, leading to increased usage of dissimilar materials. Suitable joining methods are necessary for a reliable dissimilar structure. The objective of this paper is to analyze electromagnetic impulse technology, one of the solid state welding technologies for joining of aluminium tube to coated steel rods. In the present work, electromagnetic pressure required for joining is estimated and the mechanical behaviour of the workpiece is analysed for the electromagnetic compressive force developed due to the interaction of induced current between the coil and the tubular workpiece.

Theoretical and experimental study of liquid infiltration propelled by electromagnetic pressure

We demonstrate how the axial component of electromagnetic pressure, which is generated by the impulse current in solenoid coils, can propel infiltration of microchannels using molten metals. The generated electromagnetic pressure was theoretically studied, and the results were compared with the critical pressure calculated using the capillary law. Then, the minimum current required to initiate infiltration when metals could not wet the template was determined. A self-designed electromagnetic infiltration apparatus was employed to study the experimental phenomenon. Experiments were conducted with calculated minimum current or low values by means of infiltration. The obtained microstructural images clearly revealed the full infiltration of microchannels when currents were equal to minimum values. However, when the current was lower than the critical value, electromagnetic pressure was insufficient to overcome capillary resistance in marginal areas. The insufficiency was primarily due to the radial decrease in electromagnetic pressure. When currents were further decreased, the proportion of fully infiltrated areas reduced gradually to zero, which was in good agreement with calculations. This study may represent the effective application of electromagnetic pressure in microchannel infiltration and the regulation of infiltration effects by adjusting current values. Methodologies and conclusions may also be used as guides in the future design and fabrication of composites using the electromagnetic method.

Jet in jet in M87

New high-resolution Very Long Baseline Interferometer observations of the prominent jet in the M87 radio galaxy show a persistent triple-ridge structure of the transverse 15-GHz profile with a previously unobserved ultra-narrow central ridge. This radio structure can reflect the intrinsic structure of the jet, so that the jet as a whole consists of two embedded coaxial jets. A relativistic magnetohydrodynamic model is considered in which an inner jet is placed inside a hollow outer jet and the electromagnetic fields, pressures and other physical quantities are found. The entire jet is connected to the central engine that plays the role of a unipolar inductor generating voltage between the jets and providing opposite electric currents, and the charge neutrality and current closure together with the electromagnetic fields between the jets can contribute to the jet stabilization. The constant voltage is responsible for the similar widening laws observed for the inner and outer jets. This jet-in-jet structure can indicate simultaneous operation of two different jet-launching mechanisms, one relating to the central supermassive black hole and the other to the surrounding accretion disc. An inferred magnetic field of 80 G at the base is sufficient to provide the observed jet luminosity.

Main Cause of Groove Formation on Rails Might be Local Electro-Explosion Phenomenon

It is proposed that the local electro-explosion is the main cause of rail groove formation on rail surface in this paper. The primary current paths between rails and armature are around the armature edges or corners. The liquid metal film formed on armature-rail interface is produced by electric heating and friction heating related with mechanical and electromagnetic pressures. The liquid film is squeezed out along the armature edges and dragged into many filaments. The filaments through which the current flows can be named as current bridge. When the current bridges stretch to certain thinness and their temperature produced by the power loss reach to a certain value, the phase transition caused by electro-explosion phenomenon happens, so that the liquid metal transforms into plasma. The plasma bombs the rail surface, like the arc cutting conductor technology, and craters the surface, resulting from material melting, evaporation, and transferring. After multilaunch accumulation, the rail groove appears. The electro-explosion intensity and the size of craters are estimated in this paper. Although the estimation is approximate and rough, it might be achieved to demonstrate the essential relationship between the electro-explosion and the groove formation.

Some Key Parameters of Different Caliber Solid-Armature Railgun Related to Linear Current Density

By introducing current carrier margin coefficient named $\alpha $ , ratio of armature thickness to armature width named $\beta $ , and ratio of armature height to armature width named $\gamma $ , equations of some key parameters of rectangular caliber railgun system, which is related to linear current density, are proposed. Then, some key parameters for different caliber railgun system are studied. Based on the analysis of electromagnetic contact pressure between armature and rail, $+ di/dt$ skin effect, velocity skin effect, and melt wear of armature, it can be obtained that current density of rail/armature interface is directly proportional to the linear current density. Thus, in order to decrease rail/armature interface current density, it is necessary to reduce linear current density. It can also be obtained that current density of rail/armature interface in current ramp-up is inversely proportional to the root of current rise time. Thus, it is necessary to increase current rise time to decrease rail/armature interface current density. Average melt wear rate of armature is directly proportional to the square of linear current density.