**Valentina Consolo, Antonino Musolino \*, Rocco Rizzo and Luca Sani**

Department of Engineering for Energy System, Territory and Construction (DESTEC), University of Pisa, Largo L. Lazzarino 1, 56122 Pisa, Italy; valentina.consolo@phd.unipi.it (V.C.); rocco.rizzo@unipi.it (R.R.); luca.sani@unipi.it (L.S.)

**\*** Correspondence: antonino.musolino@unipi.it

Received: 5 June 2020; Accepted: 12 August 2020; Published: 26 August 2020

**Featured Application: The electromechanical analysis of full 3D interacting devices is often necessary. This paper presents such an analysis applied to the system constituted by a rail launcher and its feeding generator. The adopted numerical tool has general validity and can be used in other contexts.**

**Abstract:** 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.

**Keywords:** air-core pulsed alternator; electromagnetic rail launcher; coupled analysis; computational electromagnetics; integral formulations
