Numerical 3D simulation of a full system air core compulsator-electromagnetic rail launcher

Multiphysics problems represent an open issue in numerical modeling. Electromagnetic launchers represent typical examples that require a strongly coupled magnetoquasistatic and mechanical approach. This is mainly due to the high velocities which make comparable the electrical and the mechanical response times. The analysis of interacting devices (e.g., a rail launcher and its feeding generator) adds further complexity, since in this context the substitution of one device with an electric circuit does not guarantee the accuracy of the analysis. A simultaneous full 3D electromechanical analysis of the interacting devices is often required. In this paper a numerical 3D analysis of a full launch system, composed by an air-core compulsator which feeds an electromagnetic rail launcher, is presented. The analysis has been performed by using a dedicated, in-house developed research code, named "EN4EM" (Equivalent Network for Electromagnetic Modeling). This code is able to take into account all the relevant electromechanical quantities and phenomena (i.e., eddy currents, velocity skin effect, sliding contacts) in both the devices. A weakly coupled analysis, based on the use of a zero-dimensional model of the launcher (i.e., a single loop electrical equivalent circuit), has been also performed. Its results, compared with those by the simultaneous 3D analysis of interacting devices, show an over-estimate of about 10-15% of the muzzle speed of the armature

Deformation Calculating of Electromagnetic Launcher's Rail Subjected to Sinusoidal Magnetic Pressure

The electromagnetic launcher's rail can be modeled as a beam on elastic foundation with simply supported beam by moving load. In this paper, Euler beam theory is applied to build the mechanical model, and the analytical solution of the equation subjected to sinusoidal magnetic pressure is derived in detail, which has successfully avoided the errors which are caused by using the uniform pressure to approximately replace the variable force. Numerical analysis of the influences brought from the elastic coefficient, the damping coefficient, the mass of rail, and the load's velocity on the deformation of beam by the MATLAB software show that the elastic coefficient and the load's velocity have quite obvious effect on the deformation of the beam while the damping coefficient and the mass of rail have not obvious effect on the deformation of the beam

Electromechanical coupled nonlinearity and critical velocity for electromagnetic railgun

The nonlinear electromagnetic force can change the critical velocity of the projectile for a railgun. It corresponds to the resonance state in railgun. Here, the nonlinear electromechanical coupled dynamics equations for the railgun are proposed. Based on it, the equation of the nonlinear critical velocity of the projectile is given and the effects of the electromagnetic nonlinearity on the critical velocity of the projectile are investigated. Besides it, the effects of the fire velocity on the nonlinear critical velocity are studied as well. Results show that the critical velocity of the railgun system increases when the electromagnetic nonlinearity is considered, and the nonlinear critical velocity is influenced by the system parameters such as rail current, rail thickness, rail distance, etc. A FEM analysis package, ANSYS, is used to simulate dynamics performance of the railgun system and illustrate the analytical results about critical velocities of the railgun system. The results can be used to design dynamics performance of the railgun system

Quadrupole Electromagnetic Linear Positioning System (QELPS):: Optimal Design, Modelling and Analysis for Linear Motion Application

In linear motion systems, including linear motors and actuators, precise and controlled linear motion is provided for various applications. However, they have several drawbacks: high costs, complexity, limited stroke length, high energy consumption, speed limitations, heat generation, noise and vibration, limited load capacity, environmental considerations, and integration challenges. High costs are especially significant for applications requiring high precision. The components' complexity and additional control electronics can increase maintenance and trouble-shooting requirements. Ensuring accurate and efficient operation necessitates regular maintenance. The limitation in stroke length, determined by the drive's size and guide length, can pose challenges for applications requiring long strokes. High energy consumption can be a concern, and speed limitations may be challenging. Managing heat generation is crucial to prevent component damage. Noise and vibration can be problematic, particularly in quiet applications. Integration challenges can arise when dealing with complex systems or automation processes. To overcome some of these drawbacks, an innovative coil configuration design for linear positioning system applications is proposed. The proposed design focuses on the Quadrupole Electromagnetic linear Positioning System (QELPS), comprising four coils generating a uniform electromagnetic field to produce a Lorentz force on the slider. The QELPS design is meticulously crafted using 3D modeling in ANSYS software, and the magnetic characteristics indicate the potential for scaling this model to different levels. The power circuit of the QELPS is simulated using ANSYS Simplorer and incorporates silicon-controlled rectifiers (SCR) and a pulse width modulation (PWM) pulse generator. The design achieves a force of 27.6 newtons with the paper presenting current and force plots in comprehensive detail. Furthermore, an interactive design algorithm is introduced, facilitating the customization of this model for various linear track dimensions. This research aims to advance linear drive technology and enhance linear motion applications by developing this new coil configuration design and harnessing the Quadrupole Electromagnetic System

Stockage d'énergie par supraconducteurs et lanceur électromagnétique S3EL

International audienceLes supraconducteurs permettent la réalisation de systèmes de stockage d'énergie appelés SMES, intéressants en tant que sources impulsionnelles inductives et bien adaptés à l'alimentation de lanceurs électromagnétiques à rails. Les performances en tenue au champ magnétique et en stabilité thermique des supraconducteurs de dernière génération, dits REBCO, permettent d'élargir le domaine d'application des SMES. Le projet BOSSE vise à développer la maitrise et l'utilisation de ces conducteurs à travers la fabrication de deux démonstrateurs. Le premier est un SMES à haute densité d'énergie. Les performances des rubans REBCO permettent de largement réduire la masse et le volume des SMES. Une réflexion a été menée pour tirer le meilleur parti des rubans REBCO et déterminer la topologie la plus adaptée pour atteindre notre objectif, qui est de battre le record de la densité d'énergie massique d'une bobine supraconductrice. Cet objectif rentre en conflit avec les stratégies de protection classiques des bobines supraconductrices et une approche différente est proposée. Le deuxième objectif du projet BOSSE est de construire un démonstrateur échelle réduite d'un lanceur S3EL, qui intègre le SMES autour du lanceur et tire parti du champ généré pour augmenter la poussée du projectile. Le principe et le design du S3EL sont présentés. </p

Bėgių tipo atvirojo kanalo elektromagnetinės svaidyklės magnetomechaninio efekto tyrimas

The dissertation investigates the electromagnetic launcher electromagnetic properties and their influence on mechanical construction. The main object of research is open bore two rail construction electromagnetic launcher. The dissertation aims to investigate the distribution of electromagnetic forces and their influence over the electromagnetic launcher construction volume. The work presents five tasks such as the electromagnetic and mechanical model application of the numerical model. The first task is formulated to rewiev the literature. The next two tasks are formulated to calculate the distribution of electromagnetic forces throughout the electromagnetic launcher construction volume. The last two tasks investigate the effect of the forces distribution differences over the electromagnetic launcher construction. The dissertation work consists of an introduction, four chapters, general conclusion, references, a list of publications by the author on the topic of the dissertation, a summary in Lithuanian and five annexes. The introductory chapter discusses the research problem, relevance of the work, introduces the object of the research, formulates the aim and the tasks of the work, describes the research methodology, scientific novelty of the work, considers the practical significance of the work results and defensive statements. At the end of the introduction, the publications and reports published by the author of the dissertation and the structure of the dissertation are presented. Chapter 1 is devoted to review the electromagnetic launcher analyses methods in literature. A brief overview of the adaptation and development history of electromagnetic launchers are provided. At the end of the chapter, conclusions are formulated, and the tasks of the dissertation are refined. Chapter 2 presents the structure and parameters of the electromagnetic launcher. According to this type of launcher, the electromagnetic and mechanical models were developed. The mathematical model of each modeling and boundary conditions are described, and the conclusions are presented. Chapter 3 and 4 provide the results of electromagnetic and mechanical modeling. The dependence between electromagnetic and mechanical problems are described. Conclusions are presented at the end of both sections. 4 articles have been published on the topic of the dissertation in the scientific journals included in the Clarivate Analytics Web of Science list, one article is in conference materials in the Clarivate Analytics Web of Science Proceedings database, and two is in peer-reviewed international conferencing materials. 4 presentations on the subject of the dissertation have been given in conferences at national and international levels

Numerical and Analytical Methods in Electromagnetics

Like all branches of physics and engineering, electromagnetics relies on mathematical methods for modeling, simulation, and design procedures in all of its aspects (radiation, propagation, scattering, imaging, etc.). Originally, rigorous analytical techniques were the only machinery available to produce any useful results. In the 1960s and 1970s, emphasis was placed on asymptotic techniques, which produced approximations of the fields for very high frequencies when closed-form solutions were not feasible. Later, when computers demonstrated explosive progress, numerical techniques were utilized to develop approximate results of controllable accuracy for arbitrary geometries. In this Special Issue, the most recent advances in the aforementioned approaches are presented to illustrate the state-of-the-art mathematical techniques in electromagnetics

Preliminary feasibility assessment for Earth-to-space electromagnetic (Railgun) launchers

An Earth to space electromagnetic (railgun) launcher (ESRL) for launching material into space was studied. Potential ESRL applications were identified and initially assessed to formulate preliminary system requirements. The potential applications included nuclear waste disposal in space, Earth orbital applications, deep space probe launchers, atmospheric research, and boost of chemical rockets. The ESRL system concept consisted of two separate railgun launcher tubes (one at 20 deg from the horizontal for Earth orbital missions, the other vertical for solar system escape disposal missions) powered by a common power plant. Each 2040 m launcher tube is surrounded by 10,200 homopolar generator/inductor units to transmit the power to the walls. Projectile masses are 6500 kg for Earth orbital missions and 2055 kg for nuclear waste disposal missions. For the Earth orbital missions, the projectile requires a propulsion system, leaving an estimated payload mass of 650 kg. For the nuclear waste disposal in space mission, the high level waste mass was estimated at 250 kg. This preliminary assessment included technical, environmental, and economic analyses

Review of Railgun Modeling Techniques: Computation of Railgun Force and Other Key Factors

Currently, railgun force modeling either uses the simple “railgun force equation” or finite element methods. It is proposed here that a middle ground exists that does not require the solution of partial differential equations, is more readily implemented than finite element methods, and is more accurate than the traditional force equation. To develop this method, it is necessary to examine the core railgun factors: power supply mechanisms, the distribution of current in the rails and in the projectile which slides between them (called the armature), the magnetic field created by the current flowing through these rails, the inductance gradient (a key factor in simplifying railgun analysis, referred to as L'), the resultant Lorentz force, and the heating which accompanies this action. Common power supply technologies are investigated, and the shape of their current pulses are modeled. The main causes of current concentration are described, and a rudimentary method for computing current distribution in solid rails and a rectangular armature is shown to have promising accuracy with respect to outside finite element results. The magnetic field is modeled with two methods using the Biot-Savart law, and generally good agreement is obtained with respect to finite element methods (5.8% error on average). To get this agreement, a factor of 2 is added to the original formulation after seeing a reliable offset with FEM results. Three inductance gradient calculations are assessed, and though all agree with FEM results, the Kerrisk method and a regression analysis method developed by Murugan et al. (referred to as the LRM here) perform the best. Six railgun force computation methods are investigated, including the traditional railgun force equation, an equation produced by Waindok and Piekielny, and four methods inspired by the work of Xu et al. Overall, good agreement between the models and outside data is found, but each model’s accuracy varies significantly between comparisons. Lastly, an approximation of the temperature profile in railgun rails originally presented by McCorkle and Bahder is replicated. In total, this work describes railgun technology and moderately complex railgun modeling methods, but is inconclusive about the presence of a middle-ground modeling method