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Helical coil electromagnetic launchers (HEMLs) using motion-induced commutation strategy solve the problem of synchronization control perfectly. HEMLs can meet the requirements of multiple applications such as the electromagnetic catapult, electromagnetic mortar and high-velocity coilgun. The trade-off between the velocity and efficiency is an important basis for these different applications. To optimize such objectives before actual design, the purpose of this paper is to focus on the efficient and flexible calculation model and algorithm. A novel structure of HEML is proposed after the transient simulation by this algorithm, which can improve the energy conversion efficiency and suppress the muzzle arc without affecting the velocity too much.

The equivalent circuit model of the launcher is established and the governing equations are derived. A combination of the four-stage Runge–Kutta method and the trapezoidal quadrature formula are used to solve the governing equations.

With smaller number of turns in the coils of HEML, the velocity is larger and the efficiency is lower. The non-uniform HEML is an effective option to improve the energy conversion efficiency and to suppress the muzzle arc with almost the same muzzle velocity as the conventional HEML.

The paper presents a common model and a flexible fast numerical method which can be used in multi-objective optimization of HEMLs such as the genetic algorithm. A new structure of the non-uniform HEML is proposed to improve the energy conversion efficiency and to suppress the muzzle arc of the launcher.

The work aims at investigating the law of miniaturization of a linear reluctance motor by expressing the ratio of force to mass as a function of bar position in per unit, for different scale factors. Corresponding to the same factors, inductance is also computed. Finally the ratio of the bar length to external diameter is changed and the analysis is accordingly repeated.

Introduction The Department of Electrical Engineering (EE) and Computer Science (CS) educates future national defence leaders in the theory and practice of its two disciplines and supports the overall USMA purpose of “providing the nation with leaders of character who serve the common defense”. Electromagnetic field theory and applications are fundamental to electrical engineering and play an important role in the Department's curriculum. In 1986, the Department began a modernization programme to upgrade its engineering curriculum, facilities, and equipment. This article describes the electromagnetics instructional thread in the curriculum and the laboratory facilities supporting that instruction.

The purpose of this paper is to present a new concept of a multi-module electromagnetic launcher with pneumatic assist. The authors focus on the problem of modelling a two-module electromagnetic launcher consisting of a coil-gun (module C) and a rail-gun (module R), as well as on the key problem of determining their position-dependent parameters, i.e. the resistances and inductances of discharging electrical circuits connected with the both modules. Special attention is paid to the possibility of influencing the missile’s flight via basic controller variation of the initial voltage values across the terminals of the capacitor batteries supplying current to both modules C and R.

Analysis of the electromagnetic launcher has been based on the circuit-field approach. Differential equations describing movement of the missile have been drawn from circuit theory. The Finite Element Method and the Comsol Multiphysic program were used to determine position-dependent parameters in module C. It is worth emphasising that the effect of saturation (resulting from B-H curve for ferromagnetic part of the considered magnetic circuit) was taken into account. The influence of the initial missile speed adjusted in a pneumatic assist unit on the missile’s velocity was also considered and illustrated by appropriate simulations (the Matlab program).

In analysing the flight of a missile along coil-gun and rail-gun modules, it is necessary to distinguish between three specific stages of the moveable element: the “fall in” stage, the “drive through” stage and the “fall out” stage. One of the most important findings is that during modelling, it is necessary to take into account of all the three above-mentioned stages of missile movement and, in particular, the “fall in” stage. It was shown both by computer simulations and laboratory investigations that this stage plays an important role in determining the time curves of decaying currents in discharging electrical circuits of both module C and module R.

The main difficulties are related to determining the influence of air drag force upon missile movement (especially in module C), as well as identifying an accurate value for contact resistances and friction force between the rails and the missile in module R.

Hybrid construction employing propelling units of different characters should be treated as a promising and challenging trend in developing launcher structure. One of the most significant advantages of such a solution is the possibility of influencing missile velocity during its flight.

Since the first device was successfully completed in 1920 the continuous rise in the interest on electromagnetic launchers has been observed. As far as their social and technical impact is concerned, one of the most promising fields of interest seem to be launchers of satellites, high-pressure compressors, simulators modelling collisions between meteoroids and the surface of the earth and electromagnetic guns on board war ships.

The novel concept in developing the construction of launchers presented in this paper has been to integrate propelling modules of different characteristics and to create a new multi-module constructional-compact whole. The designed and constructed prototype consists of three modules: a pneumatic drive unit and two electromagnetic drive units that have different principles of operation. The original methodology leading to the creation of its effective mathematical model (focusing on determination of position-depended parameters) was presented and verified in an experimental way.

The purpose of this paper is to elaborate algorithm and software for the optimization of the actuator–capacitor system taking the dynamics parameters into account. The system is applied for driving the valve of plasma gun. Two optimization strategies are proposed and pondered. The penalty function approach has been expanded in detail.

The field-circuit mathematical model of the dynamics operation consists of the strongly coupled equations of the transient electromagnetic fields and the equations of the electric circuit. The numerical implementation is based on finite element method and step-by-step Cranck–Nicholson procedure. The genetic algorithm has been used in the optimization procedure. The sigmoidal transformation has been applied to adjust the classical external penalty function method to the genetic algorithm.

The modification consists in adaptation of the penalty function to the genetic algorithm. In the proposed approach, operations involving successive iterations of increasing penalty function and operations containing genetic iterations are intertwined with each other. The differences between these two procedures are getting blurred. The proposed approach is very effective. It is possible to achieve optimal solution even more than ten times faster than using the classical method.

The proposed approach can be successfully applied to designing and optimization of different electromagnetic devices, including functional constraints.