Electrodynamic Forces Research Articles

Take-off aided by magnetic levitation technology

Purpose – The purpose of the paper is to analyze changes in the selected characteristics of an aircraft aided by a ground-based system using magnetic levitation (MAGLEV) to support safe take-off. Design/methodology/approach – The analysis of the mass characteristics of the main aircraft units with conventional constructing solutions was carried out in this paper. It allowed determining the mass of these units and verifying the obtained results on the basis of the known examples. Thanks to such an approach it was possible to determine the mass of the aircraft modified for the requirements of the ground and on-board system for support of the aircraft safe take-off and landing (GABRIEL) system taking into account the change in the weights of the modified units (fuselage, wings, power unit, landing gear, etc.). The weight of the aircraft in its basic version was determined on the basis of the common knowledge and methods described in the scientific literature which are based on the statistical analysis. The weight of the modified units for the needs of the GABRIEL system was determined on the basis of similar formulas taking into account the constructional changes in the airframe. The thrust required of the power unit was determined on the basis of the analysis of the steady state of the horizontal flight for the calculating aerodynamic characteristics determined by conventional methods. The characteristics in the take-off phase were determined solving the equation of motion of the aircraft influenced by the aerodynamic, electrodynamic forces and the forces that come from the power unit. Findings – The preliminary analysis shows that the take-off aid system that uses the phenomenon of MAGLEV is possible to be created using the present-day technology. However, the costs of its realization would make it economically unproved. But it could increase safety and reduce harmful influence on the environment caused by taking-off and landing aircrafts. Research limitations/implications – The analysis was carried out only for one chosen version of the solution which according to the author has the greatest chance to succeed. At the present-day state of the art, it seems problematic to use the proposed system to aid landing. Practical implications – The work shows a practical possibility to implement the proposed solution. The results of the analyses are a separate point for further research of similar systems. Originality/value – The work presents one of the aspects of the potential application of the innovatory conception of take-off and landing aid of transport aircrafts by the ground-based system using the MAGLEV technology.

Spatial transfer of conductive plate through decoupling of two axial electrodynamic forces generated by magnet wheel

The partial shielding of the magnetic field generated by a magnet wheel that rotates under a conductive plate generates two linearized axial electrodynamic forces similar to those generated by a linear induction motor on the plate over the non-shielded open area. The forces are strongly coupled by the rotating speed of the magnet wheel, which is the only control variable. Therefore, to position the plate in space as desired, another control variable besides the wheel speed is needed. So, in this paper, the absolute size of the open area is proposed as a new variable. Around the nominal rotating speed, the normal force is much more sensitive than the thrust force to the speed of the wheel. Therefore, the speed roughly corresponds to the normal force, and the size of the open area corresponds to the thrust force. Of course, a variation of the normal force due to a change in size of the open area should be compensated by controlling the wheel speed. As another case for the positioning of a conductive plate, the in-plane positions of the plate can be controlled indirectly by out-of-plane control with respect to the target air–gaps obtained by the in-plane controller. Although the only controlled variable is the air–gap lengths, in-plane control forces are reflected in determining the air–gap lengths. The above methods are verified experimentally.

Control for the Lift of the Inlet Valve - Electromagnetic Drive Assembly with the Effect of Friction

It has been analyzed the assembly of electromagnetic drive - inlet valve operating in camless valvetrain. The valve made of TiAl alloy has mated with its guide made of phosphor bronze. The scheme of electromagnetic valve drive has been shown in the article. The head aim of the motion control for such valve has been to provide small values of the valve velocity near the valve seat position. The aim of present analysis is to study the course of friction force between valve stem and its guide against time during use of control algorithm presented in the article. Curses of generated electrodynamical force against displacement of coil - valve assembly has been computed using FEM method and presented in the article. The courses of valve lift against time for different conditions have been presented in the article.

Long term dynamics and optimal control of nano-satellite deorbit using a short electrodynamic tether

This paper studies the long term dynamics and optimal control of a nano-satellite deorbit by a short electrodynamic tether. The long term deorbit process is discretized into intervals and within each interval a two-phase optimal control law is proposed to achieve libration stability and fast deorbit simultaneously. The first-phase formulates an open-loop fast-deorbit control trajectory by a simplified model that assumes the slow-varying orbital elements of electrodynamic tethered system as constant and ignores perturbation forces other than the electrodynamic force. The second phase tracks the optimal trajectory derived in the first phase by a finite receding horizon control method while considering a full dynamic model of electrodynamic tether system. Both optimal control problems are solved by direct collocation method base on the Hermite–Simpson discretization schemes with coincident nodes. The resulting piecewise nonlinear programing problems in the sequential intervals reduces the problem size and improve the computational efficiency, which enable an on-orbit control application. Numerical results for deorbit control of a short electrodynamic tethered nano-satellite system in both equatorial and highly inclined orbits demonstrate the efficiency of the proposed control method. An optimal balance between the libration stability and a fast deorbit of satellite with minimum control efforts is achieved.

On the possibility of long-time existence of submicron particles injected in elongated elliptical orbits with low perigee in the near-Earth space

On the basis of numerical experiments the theoretical possibility of long-time (longer than 1 month) and superlong-time (longer than 1 year) existence in orbit of technogenic microparticles (MPs) with radii of a few hundredths of a micrometer is demonstrated. MPs are injected into the near-Earth space (NES) in elongated elliptical low-perigee orbits with parameters, corresponding to Molniya satellite’s orbital parameters. Calculations were carried out taking into account disturbing effects on the MP orbital motion in NES of the following factors: the gravitational disturbance caused by polar oblateness of the Earth, the solar pressure force (calculated with using the techniques of the Mie theory), the drag force of a neutral component of background gas, as well as the electrodynamic forces caused by interaction of electric charge, induced on MPs, with the magnetic and electric fields of the NES.

Libration dynamics and stability of electrodynamic tethers in satellite deorbit

This paper studies libration dynamics and stability of deorbiting nano-satellites by short and bare electrodynamic tethers. A critical aspect of satellite deorbit by an electrodynamic tether is to maintain the tether aligned with the local vertical and stable while subjected to external perturbations. The dynamics of electrodynamic tether system in deorbit application is divided into the orbital motion of the center of system’s mass and the tether libration motion relative to that center. Major space environmental perturbations including the current-induced electrodynamic force, atmospheric drag, oblateness effect of the Earth, irregularity of geomagnetic field, variable plasma density, solar radiation pressure, and lunisolar gravitational attractions are considered in the dynamic analysis. Quantitative analyses are provided in order to characterize the order of the perturbative torques during the deorbit process. A single index is derived from the libration energy to stabilize the libration motion by regulating the current in the tether through simple on-off switching. Numerical results show that the libration dynamics of an electrodynamic tether has significant impacts on the deorbit process and the electrodynamic tether cannot effectively deorbit satellites without libration stability control. The proposed current regulation strategy is simple and very effective in stabilizing libration motion of an electrodynamic tether.

Effective Collection and Detection of Airborne Species Using SERS‐Based Detection and Localized Electrodynamic Precipitation

Three different delivery concepts (standard diffusion, global electrodynamic precipitation, and localized nanolens-based precipitation) and three different SERS enhancement layers (a silver film, a nanolens-based localized silver nanoparticle film, and the standard AgFON) are compared. The nanolens concept is applied to increase the SERS signal: a factor of 633, when compared to a standard mechanism of diffusion, is observed.

Simulation and Analysis Package Development of Short-Circuit Electrodynamic Force of Power Transformer Windings

This study presents the calculation method for short-circuit electrodynamic force of power transformer winding and development of electrodynamic force analysis software package. Finite element method is used to achieve the leakage magnetic field of transformer winding under short circuit operation. Electromagnetic force is calculated by using Lorentz force formula. Based on mechanical properties of kraft-manila paper and press-board, which are used as insulation and reinforcement materials, considering the elastic force and friction of the various insulating materials, the equivalent mass spring model of winding is established and axial dynamic force and displacement is calculated. Using client/server mode, short-circuit electrodynamic force analysis software for power transformer winding is developed, which consists of several sub-system, such as parameter input and calculation and result analysis. The client/server structure facilitates the expansion of the software features. This software package has been applied in the power transformer manufacture enterprise.

Contact Parameter Computation and Analysis of Air Circuit Breaker with Permanent Magnet Actuator

An air circuit breaker (ACB) with novel double-breaker contact and permanent magnet actuator (PMA) is presented. Three-dimensional (3-D) finite element method (FEM) is employed to compute the electro-dynamic repulsion forces, including the Holm force and Lorentz force, which are acting on the static and movable contacts. The electro-dynamic repulsion forces of different contact pieces are computed, illustrating there is an optimal number of contact pieces for the ACB being studied. The electro-dynamic repulsion force of each contact, which varies from the outer position to the inner position, is also computed. Finally, the contacts of the double-breaker are manufactured according to the analyzed results to validate the simulations.

Ultrahigh Acceleration of Plasma Blocks by Nonlinear Forces for Side-On Laser Ignition of Solid Density Fusion Fuel

A fundamental difference of very high intensity laser interaction with plasmas from solid targets appears with lasing at picosecond (ps) pulse durations in contrast to pulses of nanoseconds (ns). This can be seen from the more than 10,000 times higher acceleration with ps pulse durations than with thermal pressure determined interaction. A ps pulse duration produces instantly acting high-efficiency nonlinear (ponderomotive) electrodynamic force dominated acceleration in contrast to heating with longer pulses. The ps pulses accelerate high-density plasma blocks. This can be used by a new scheme of side-on driven laser fusion with generating a flame ignition in uncompressed fusion fuel of solid density resulting in a reaction velocity of more than 2000 km/s for DT.

Dynamics of Nanosatellite Deorbit by Bare Electrodynamic Tether in Low Earth Orbit

This paper studies the dynamics of nanosatellite deorbit by a bare electrodynamic tether. The orbital dynamics of the tethered nanosatellite is modeled in Gaussian perturbation equations and the motion-induced voltage-current relationship along the electrodynamic tether is analyzed by using the 2000 International Geomagnetic Reference Field model including up to seventh-order terms and the International Reference Ionosphere 2007 model. The analysis reveals that the high-order magnetic model of Earth affects the dynamic characteristics of the tethered nanosatellite, especially in orbits with high inclination angles, by changing its orbit from circular to elliptical forms. This is beneficial for deorbiting the nanosatellite in near-polar orbits where the electrodynamic force is not as effective as in the equatorial orbit because the denser atmosphere at a lower perigee will provide a larger atmospheric drag. Moreover, the analysis shows that the electrodynamic force is always against the satellite motion in low Earth orbit even when the induced voltage/current across the tether reverses their polarities in near-polar orbits. Compared to the deorbit rate by the atmospheric drag only, the deorbit rate by an electrodynamic tether will be increased by several orders in magnitudes in both equatorial and polar orbits.

Metamorphic manipulating mechanism design for MCCB using index reduced iteration

The present research on moulded case circuit breaker(MCCB) focuses on the enhancement of current-limiting interrupting performance during short circuit, overload, under voltage and phase failure, involving electrics, magnetic, mechanics, thermal, material, friction, arc extinguishing, impact vibration, skin effect, etc. The rigid-flexible coupling of the parts and components of the metamorphic manipulating mechanism in multi-fields leads to the non-rigid, high frequency, high damping, singularity of the Euler-Lagrange equations which represents the multi-body dynamics. The small step iteration which is used for obtaining the instantaneous and short time critical interrupting performance of metamorphic mechanism appears inaccuracy. It is difficult to realize top-down design by existing CAD systems. Therefore, a metamorphic manipulating mechanism design method for MCCB using index reduced iteration(IRI) is put forward. The metamorphic manipulating mechanism of MCCB is decomposed into three mechanisms: main switch connector mechanism, electromagnet-drawbar-jump buckle mechanism, and bimetallic strip-drawbar mechanism, which is respectively described by electro-dynamic force, electromagnet force, and bimetallic strip force. The dummy part(virtual rigid) without moment of inertia and mass is employed as intermediate to join the flexible body and rigid body. The model of rigid-flexible coupling metamorphic mechanism multi-body dynamics is built. The differential algebraic equations(DAEs) of the multibody dynamics model are converted to pure ordinary differential equations(ODEs) by coordinate partition. Order reduced integration with multi-step and variable step-size is preceded based on IRI. The non-linear algebraic equations are solved in each integration step by Newton-Rapson iteration. There is no ill-condition and singularity of Jacobian matrix when step size reduces to zero. The independent prototype design system using ACIS R13, HOOPS V11.0 and Visual C++.NET 2003 has been developed, which verifies the effectiveness of the proposed method. The proposed method enhances the current-limiting interrupting performance of MCCB, and has reference significance for multi-body dynamics design for similar flexible metamorphic mechanisms in multi-fields.

On determining pinch-effect electrodynamic forces that act on the electric arc in a three-phase arc steelmaking furnace

This article discusses a method of determining the electrodynamic forces that develop when the current of an electric arc interacts with its magnetic field (the pinch effect). The character of distribution of the pressure created by these forces over the radius of the arc and the correctness of determining the axial force by rotating the pinch-effect force by 90° are also discussed. The authors give their point of view on the calculation and distribution of pinch-effect pressure and the method used to determine the axial force that acts on the arc. They also offer their own interpretation of the processes associated with the combustion of an arc in three-phase electric-arc steelmaking furnaces.

Biophysical insights into cancer transformation and treatment.

Biological systems are hierarchically self-organized complex structures characterized by nonlinear interactions. Biochemical energy is transformed into work of physical forces required for various biological functions. We postulate that energy transduction depends on endogenous electrodynamic fields generated by microtubules. Microtubules and mitochondria colocalize in cells with microtubules providing tracks for mitochondrial movement. Besides energy transformation, mitochondria form a spatially distributed proton charge layer and a resultant strong static electric field, which causes water ordering in the surrounding cytosol. These effects create conditions for generation of coherent electrodynamic field. The metabolic energy transduction pathways are strongly affected in cancers. Mitochondrial dysfunction in cancer cells (Warburg effect) or in fibroblasts associated with cancer cells (reverse Warburg effect) results in decreased or increased power of the generated electromagnetic field, respectively, and shifted and rebuilt frequency spectra. Disturbed electrodynamic interaction forces between cancer and healthy cells may favor local invasion and metastasis. A therapeutic strategy of targeting dysfunctional mitochondria for restoration of their physiological functions makes it possible to switch on the natural apoptotic pathway blocked in cancer transformed cells. Experience with dichloroacetate in cancer treatment and reestablishment of the healthy state may help in the development of novel effective drugs aimed at the mitochondrial function.

Long-Term Libration Dynamics and Stability Analysis of Electrodynamic Tethers in Spacecraft Deorbit

AbstractElectrodynamic tether systems orbiting the Earth are prone to libration instability because of periodic changes in the geomagnetic field, plasma density, and lunisolar gravitational attractions in addition to nonperiodic changes resulting from the irregularity of the geomagnetic field, inhomogeneity of the Earth, and solar pressures. The long-term orbital and libration dynamics of a bare electrodynamic tether in deorbiting obsolete satellites is investigated by considering space environmental perturbations of current-induced electrodynamic force, atmospheric drag, Earth’s oblateness, irregularity of the geomagnetic field, variable space plasma density, solar radiation pressure, and lunisolar gravitational attractions. The electrodynamic tether is assumed to be rigid and the tethered spacecraft is modeled as a lumped mass. The study shows by numerical simulation that the out-of-plane libration is the primary source of libration instability in inclined orbits, which destabilizes the in-plane librati...

Analysis of electromagnetic forces in high voltage superconducting fault current limiters with saturated core

This paper presents a three-dimensional numerical analysis of the electromagnetic forces within a high voltage superconducting fault current limiter (FCL) with a saturated core under short-circuit conditions. The effects of electrodynamic forces in power transformer coils under short-circuit conditions have been reported widely. However, the coil arrangement in an FCL with saturated core differs significantly from existing reactive devices. The boundary element method is employed to perform an electromagnetic force analysis on an FCL. The analysis focuses on axial and radial forces of the AC coil. The results are compared to those of a power transformer and important design considerations are highlighted.

Comment on “Finite Size Corrections to the Radiation Reaction Force in Classical Electrodynamics”

In [1, arXiv:1005.2617] effective field theory methods have been employed to compute the equations of motion of a spherically symmetric charged shell of radius R, taking into account the radiation reaction force exerted by the shell's own electromagnetic field up to O(R^2). The authors of Ref. [1] have stated that the known result for the self force of the shell as can be found from Eq. (16.28) of the textbook of Jackson [2] (see also Chap. 4 in the review of Pearle [3]) is incorrect, in that the term linear in R should be absent. We claim that this conclusion of Ref. [1] is incorrect, and that the textbook result, Eq. (1) does hold.

Numerical Simulation of Digital Microfluidics Based on Electro-Dynamic Model

Aiming at the doubt and divarication about the internal mechanism of electrowetting on dielectric (EWOD) in digital microfluidics, the authors attempted to explain the internal mechanism of EWOD through electro-dynamic-based numerical simulation model. First, the boundary conditions for the governing equation were found. Then the influence of mesh number on simulation results was analyzed and feasibility of the simulation model was verified by comparing numerical results with theoretical ratiocination. Finally, they compared the electro-dynamic actuation force acting on the surface of droplet on three digital microfluidic structures, which have the same three-phase contact line but different area of contact domain. Analytical results showed that electro-dynamic force generated solely by the accumulation of induced charges in contact domain was three times larger than that generated by three-phase contact line. Induced charges accumulated on both three-phase contact line and contact area of droplet gave the contribution to EWOD, but contact area played a major role in the change of contact angle of droplet.

On the Molecular Mechanism of Stabilization of Proteins by Cosolvents: Role of Lifshitz Electrodynamic Forces

Several ionic and nonionic additives are known to affect structural stability of proteins in aqueous solutions. At a fundamental level, the mechanism of stabilization or destabilization of proteins by cosolvents must be related to three-body interactions between the protein, additive, and the water medium. In this study, the role of the Lifshitz-van der Waals electrodynamic interaction between various additives (sucrose, glycerol, urea, poly(ethylene glycol)-200, betaine, taurine, proline, and valine) and bovine serum albumin (BSA) in water medium was examined. The electrodynamic interaction energy was attractive for all of the additives studied here when both far ultraviolet and infrared relaxations of the additives were included in their dielectric susceptibility representations. However, when only the infrared contribution was included for structure stabilizers and both far ultraviolet and infrared contributions for the structure destabilizers, the resulting electrodynamic interaction energy (E/kT) followed the structure stabilizing and/or destabilizing behavior of the additives; that is, the interaction was attractive for urea and PEG200 (structure destabilizers), whereas it was repulsive for sucrose, glycerol, betaine, taurine, alanine, valine, and proline (structure stabilizers). The electrodynamic interaction energy E/kT at any given surface-to-surface separation distance between the additives and BSA was positively correlated (r(2) = 0.92) with the experimental thermal denaturation temperature (T(d)) of BSA in 1 M solutions of the additives. These analyses provided a mechanistic basis for the experimental observations of exclusion of the structure-stabilizing additives from the protein-water interface and binding of the structure-destabilizing additives to the protein surface. The role of water structure in the three-body electrodynamic interaction is discussed. It is hypothesized that in the case of additives that enhance water structure the hydration shells formed around the additives effectively dampen the contribution of ultraviolet frequencies to the dielectric susceptibility of the additives and thus impart repulsive electrodyanamic interaction between the additive and the protein, whereas the opposite occurs in the case of additives that breakdown the hydrogen-bonded structure of water.

Coupled Three Dimensional Numerical Calculation of Forces and Stresses on the End Windings of Large Turbo Generators via Integral Formulation

A novel numerical approach to calculate the time evolution of the three dimensional distribution of the magnetic field and forces in the end winding regions of large turbine generators is presented. The proposed approach is based on an integral formulation for nonlinear magnetostatic problems. Its main advantage is the reduction of the discretization to only the conductors and magnetic materials. In this paper the solution of a coupled magnetostructural problem consisting in the calculation of the mechanical stresses and deformations caused by the electrodynamic forces is presented. The analysis is based on a time stepping simulation where the currents are derived from the integration of a lumped parameter model.