Experimental results and performance analysis of a 500 m/sec linear induction launcher (LIL)

Abstract

A computer model, previously validated, was used to study the performance of an experimental 3-phase launcher energized by a capacitor bank and designed to impart to a 137-gram projectile a muzzle velocity of 500 m/s: (1) the build-up of the traveling wave was examined; (2) the connection of the drive coils was changed; (3) the resistances of the drive circuits were calculated and measured; (4) the effect of the conductivity of the cylindrical tube (sleeve) constituting the projectile was assessed.Experimentally, a doubling of the muzzle velocity was achieved, from an earlier-obtained 250 m/s, to its present 476 m/s. This was done by strengthening the thin-walled aluminum sleeve by heat-treatment (aging) to prevent it from being crushed when the input energy was raised to its design value.

In-bore projectile dynamics in the linear induction launcher (LIL). Part II: balloting, spinning, and nutation

“…This was shown in Since the equivalent force is not acting on the mass center, the projectile, while propelled, has a torque about the mass center. The time dependence of the torque T was obtained by simulation [ l ] for the Model 3 LIL, an experimental prototype [2] at the Polytechnic, and is shown in It is apparent that, as a consequence of the asymmetric distribution of the restoring force, the projectile may tend to exhibit oscillatory behaviors [3,4], including a tendency to ballot; i.e.. a tendency for the head and tail ends of the projectile to rock from side to side within the barrel. The practical importance of these oscillations depends partly on whether or not the transit time of the projectile through the barrel is considerably shorter than the oscillatory period.…”

Research on Accelerative Characteristics of Three Kinds of Coaxial Induction Coil Launchers

“…The researches on ODCICLs have been made widely and deeply, but the researches on IDCICLs and IODCICLs have not been found in existing literature. How to improve the launch efficiency is the most important goal for researchers pursuing whether coaxial synchronous induction coil launchers or coaxial asynchronous induction coil launchers [6]- [9]. Recently, the performance of coaxial synchronous induction coil launchers has been investigated by means of the tool of MATLAB [10].…”

Design of an Electromagnetic Launcher for Earth-to-Orbit (ETO) microsatellite systems

“…A Linear Induction Launcher (LIL) is an air-cored coilguntype launcher operates on the same principle of a linear induction motor [12]- [14]. It consists of two parts: The stationary part, which is called the barrel, is where a magnetic traveling wave is generated.…”