Date

2022-01-01

Author

Tosun, Nail
Civil, Anil
Oruc, Ahmet Yasin
Yildirim, Baran
Ozceylan, Bekir Mert
Bolat, Bora
Yurdakul, Emre Burak
Tan, Evren
Yurdakonar, Ferhat
Akdemir, Huseyin
Gungen, Ibrahim
Onur, Ibrahim
Karagoz, Mustafa
Cavbozar, Ozgur
Demirkol, Rasih Hakan
Gocmen, Ulas
Keysan, Ozan

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

146
views

0
downloads

Cite This

ASELSAN Inc. has been working on electromagnetic launch technologies since 2014. The first prototype, EMFY-1, has a 25 mm x 25 mm square bore and 3-m-length rails. The second prototype, EMFY-2, has a 50 x 50 mm square bore and 3-m-length. This article presents a recently developed prototype, EMFY-3, with a 50 x 75 mm rectangular bore and 6-m length. The input energy of the pulsed-power supply (PPS) is doubled to 8 MJ, and the 2.91 MJ muzzle energy is obtained. Velocity curves are captured with Doppler radar, enabling us to establish propulsive inductance gradient $L{'}_{{pr}}$ transients empirically. The results confirm that $L{'}_{{pr}}$ is constant throughout the launch, as no significant breaking mechanism occurs with the non-magnetic containment. However, a slight variation (2% at maximum) happens with different rails' current magnitudes from one launch to another. The transition phenomenon is a candidate for the drop in the $L{'}_{{pr}}$ , as it occurs more likely at launches with higher linear current densities. Moreover, a sensitivity analysis is conducted to show the importance of $L{'}_{{pr}}$ calculations. A deviation of 5% from the actual value can cause an error in muzzle velocity up to 6.2%. This fact indicates that simulation models are very susceptible to $L{'}_{{pr}}$ calculations. Although $L{'}_{{pr}}$ is calculated as 0.515 mu H/m with 3-D finite element method (FEM), the Kerrisk formula calculates as if 0.561 mu H/m; the experimental measurement gives 0.575 mu H/m. These methods differ by 8% at maximum, which causes muzzle velocities errors. Regarding empirical findings, the 3-D FEM model calculates $L{'}_{{pr}}$ more precisely than analytical formulas, and the contrast between models have grave importance due to the muzzle velocity errors.

Subject Keywords

Rails, Drag, Inductance, Mathematical models, Friction, Aerodynamics, Force, Electromagnetic launchers (EMLs), finite-element (FE) analysis, muzzle voltage, pulsed-power supply (PPS), railgun, transition, TRANSITION, MODEL, SIMULATION, TRANSIENT, VELOCITY

URI

https://hdl.handle.net/11511/95345

Collections

Department of Electrical and Electronics Engineering, Article