Characteristics of Plasma Dynamics in Current Sheets Formed in Helium Plasma

The characteristic features of plasma acceleration in the current sheets are discussed on the basis of an analysis of the structure of electrodynamic forces at successive stages of the evolution of the current sheets formed in the plasma with helium ions. Of particular interest is the generation of reverse currents at the side edges of the sheet and the appearance of forces, which are braking previously accelerated plasma flows.

Agent-based Models for Detecting the Driving Forces of Biomolecular Interactions

Agent-based modelling and simulation have been effectively applied to the study of complex biological systems, especially when composed by a large number of interacting entities. Representing biomolecules as autonomous agents allows this approach to bring out the global behaviour of biochemical processes as resulting from local molecular interactions. In this paper, we leverage the capabilities of the agent paradigm to construct an in silico replica of the glycolytic pathway of baker’s yeasts; the aim is to detect the role that long-range electrodynamic forces might have on the rate of glucose oxidation. Experimental evidences have shown that random encounters and short-range potentials might not be sufficient to explain the high efficiency of biochemical reactions in living cells. However, while the latest in vitro studies are limited by the present-day technology, agent-based simulations provide an in silico support to the outcomes hitherto obtained and shed light on behaviours not yet well understood. Our results reveal to be able to grasp properties hard to uncover through other computational methods, such as the effect of electromagnetic potentials on glycolytic oscillations.

Determination of mutual inductances and electrodynamic forces between the coil and the coaxial solenoid in a symmetrical arrangement

Object and purpose of research. Mutual inductances are among the main parameters of electrical circuits, and their determination is the most important task for studying the physical processes occurring in them, including the occurrence of electrodynamic forces. Coaxial coils and solenoids are very common part of electrical devices, and finding mutual inductances and electrodynamic forces in them has a great practical importance. Materials and methods. Methods of theoretical electrical engineering are used. Main results. Expressions for mutual inductance are obtained, and they are based on the decomposition of the solenoid into its external and internal parts relative to the end planes of the coil. Conclusion. On the basis of the undertaken analysis, alternative expressions for mutual inductances are obtained.

EXCITATION OF A PULSE ELECTROMECHANICAL CONVERTER OF ELECTRODYNAMIC TYPE FROM A TWO-SECTION CAPACITOR ENERGY STORAGE

A mathematical model of a pulsed electromechanical converter (PEC) of electrodynamic type has been developed, in which the solutions of the equations are presented in a recurrent form, which, when numerically implemented, allows taking into account the interrelated electrical, magnetic, mechanical and thermal processes and their nonlinear parameters. While maintaining the total energy of the pulsed source, the influence of the distribution of energy between the two sections of the capacitive energy storage (CES) and the voltage at which the additional section of the CES is connected was established. When operating in an accelerating mode, the largest amplitude of electrodynamic forces (EDF) and maximum speed occur in the basic version of the PEC, which is excited only from the main section of the CES, and the most effective is the PEC with the smallest capacity of the main section of the CES, and its maximum value is 2.61 higher than for the basic version of the PEC. When operating in the shock-power mode, compared with the basic version of the PEC, the amplitude of the EDF decreases. The most effective is the PEC with the smallest capacity of the main section of the CES, and its maximum value is 5.17 higher than that of the basic version of the PEC. Experimental studies of the PEC in the shock-power mode established that the oscillograms of the voltage of the CES and the current of the PEC correspond to the calculated characteristics, and their main indicators are consistent with each other with an accuracy of 5-7%. References 16, figures 6.

Calculations of Electrodynamic Forces in Three-Phase Asymmetric Busbar System with the Use of FEM

Proper busbar selection based on analytical calculations is of great importance in terms of power grid functioning and its safe usage. Experimental tests concerning busbars are very expensive and difficult to be executed. Therefore, the great advantage for setting the valid parameters for busbar systems components are analytical calculations supported by FEM (finite element method) modelling and analysis. Determining electrodynamic forces in busbar systems tends to be crucial with regard to subsidiary, dependent parameters. In this paper analytical calculations of asymmetric three-phase busbar system were carried out. Key parameters, like maximal electrodynamic forces value, mechanical strength value, busbar natural frequency, etc., were calculated. Calculations were conducted with an ANSYS model of a parallel asymmetric busbar system, which confirmed the obtained results. Moreover, showing that a model based on finite elements tends to be very helpful in the selection of unusually-shaped busbars in various electrotechnical applications, like switchgear.

Maxwell Equations Without a Polarization Field, Using a Paradigm from Biophysics

Electrodynamics is usually written using polarization fields to describe changes in distribution of charge as electric fields change. This approach does not specify polarization fields uniquely from electrical measurements. Many polarization fields will produce the same electrodynamic forces and flows because only divergence of polarization enters Maxwell’s first equation, relating charge and electric field. The curl of any function can be added to a polarization field without changing the electric field at all. The divergence of the curl is always zero. To be unique, models must describe the charge distribution and how it varies. I propose a different paradigm to describe field dependent charge, i.e., the phenomenon of polarization. This operational definition of polarization has worked well in biophysics for fifty years, where a field dependent, time dependent polarization provides gating current that makes neurons respond sensitively to voltage. Theoretical estimates of polarization computed with this definition fit experimental data. I propose that operational definition be used to define polarization charge in general. Charge movement needs to be computed from a combination of electrodynamics and mechanics because ‘everything interacts with everything else’. The classical polarization field need not enter into that treatment at all. When nothing is known about polarization, it is necessary to use an approximate representation with a dielectric constant that is a single real positive number. This approximation allows important results in some cases, e.g., design of integrated circuits in silicon semiconductors, but can be seriously misleading in other cases, e.g., ionic solutions.

Maxwell Equations Without a Polarization Field, Using a Paradigm from Biophysics

Electrodynamics is usually written using polarization fields to describe changes in distribution of charge as electric fields change. This approach does not specify polarization fields uniquely from electrical measurements. Many polarization fields will produce the same electrodynamic forces and flows because only divergence of polarization enters Maxwell’s first equation, relating charge and electric field. The curl of any function can be added to a polarization field without changing the electric field at all. The divergence of the curl is always zero. To be unique, models must describe the charge distribution and how it varies. I propose a different paradigm to describe field dependent charge, i.e., the phenomenon of polarization. This operational definition of polarization has worked well in biophysics for fifty years, where a field dependent, time dependent polarization provides gating current that makes neurons respond sensitively to voltage. Theoretical estimates of polarization computed with this definition fit experimental data. I propose that operational definition be used to define polarization charge in general. Charge movement needs to be computed from a combination of electrodynamics and mechanics because ‘everything interacts with everything else’. The classical polarization field need not enter into that treatment at all. When nothing is known about polarization, it is necessary to use an approximate representation with a dielectric constant that is a single real positive number. This approximation allows important results in some cases, e.g., design of integrated circuits in silicon semiconductors, but can be seriously misleading in other cases, e.g., ionic solutions.

MODELING AND MONITORING OF THERMODYNAMIC PROCESSES IN SYNCHRONOUS ELECTRIC MOTORS

Methods are given for the mathematical description of thermodynamic processes in the insulation of drive motors of alternating current megawatt class. The paper presents the requirements for equipping monitoring systems of the main technological equipment and electric machines, in particular, which regulate the monitoring of working capacity, reliability and safety of equipment using reliable technical and software tools. The most appropriate when choosing a monitoring model for synchronous motors is a functional diagnostic model, when using which the input actions of elementary checks are determined in advance by the working algorithm of the object, and only the composition of the controlled parameters of the diagnostic object is subject to selection. For a predictive analysis of the temperature of the windings of a synchronous machine, a three-stage heating theory is used, in which the motor is divided into a stator winding, a steel structure of the stator and a rotor. In addition, the models take into account the mechanical loads acting on the insulation of the stator windings in various modes during operation: electrodynamic, vibrational and thermomechanical. The results of the analysis of the dynamics of thermodynamic processes in the stator windings of machines with refinements related to the effects of cooling methods, the finning of the external surface of the machine, the heat sink through the frame and bearing shields, as well as the influence of a significant amount of air inside the thermal circuits of synchronous motors. For engineering calculations, algorithms for determining electrodynamic forces are recommended, taking into account simplifying assumptions that do not affect the accuracy of the practical assessment of the forces acting on the isolation of powerful machines. The determination of only some of the main components of the effects, which include the forces caused by the interaction of currents of one phase and acting on the extreme rod of the phase group in the involute part of the rod along the corresponding curves, is also justified.