Thermal limitations in a rapid-fire multirail launcher powered by a pulsed magnetodhydrodynamic generator

• Published in: Journal of applied mechanics and technical physics 2017-09, Vol.58 (5), p.871-880
• Main Authors: Stankevich, S. V., Shvetsov, G. A., Butov, V. G., Sinyaev, S. V.
• Format: Article
• Language: English
• Subjects: Applications of Mathematics; Classical and Continuum Physics; Classical Mechanics; Computational fluid dynamics; Computer simulation; Current density; Current distribution; Density distribution; Fluid flow; Fluid- and Aerodynamics; Heating; Launchers; Launching; Magnetism; Magnetohydrodynamic generators; Magnetohydrodynamics; Mathematical Modeling and Industrial Mathematics; Mathematical models; Mechanical Engineering; Nonuniformity; Physics; Physics and Astronomy; Projectiles; Rails; Sequences; Three dimensional models; Two dimensional models
• ISSN: 0021-8944; 1573-8620
• DOI: 10.1134/S0021894417050133

The operation of rapid burst firing multirail electromagnetic launchers of solids is numerically simulated using unsteady two-dimensional and three-dimensional models. In the calculations, the launchers are powered by a Sakhalin pulsed magnetohydrodynamic generator. Launchers with three and five pairs of parallel rails connected in a series electrical circuit are considered. Firing sequences of different numbers of solid projectiles of different masses is modeled. It is established that the heating of the rails is one of the main factors limiting the performance of launchers under such conditions. It is shown that the rate of heating of the rails is determined by the nonuniformity of the current density distribution over the rail cross-section due to the unsteady diffusion of the magnetic field into the rails. Calculations taking into account the unsteady current density distribution in the rails of a multirail launcher show that with an appropriate of the mass of the projectiles (up to 800 g), their number in the sequence, and the material of the rails, it is possible to attain launching velocities of 1.8–2.5 km/s with moderate heating of the rails.