A coil-unit barrel for a helical coil electromagnetic launcher is described. It provides better features of high structural strength and flexible adjustability. It is convenient to replace the damaged coil units and easy to adjust the number of turns in the stator coils due to the modular design. In our experiments, the highest velocity measured for a 4.5-kg projectile is 47.3 m/s and the mechanical reinforcement of the launcher could bear 35 kA peak current. The relationship between the energy conversion efficiency and the inductance gradient of the launcher is also studied. In the region of low inductance gradient, the efficiency is positively correlated with the inductance gradient. However, in the region of high inductance gradient, the inter-turn arc erosion becomes a major problem of limiting the efficiency and velocity of the launcher. This modular barrel allows further studies in the inter-turn arc and the variable inductance gradient helical coil launcher.
REFERENCES
1.
W.
Ying
and X.
Feng
, Principle of Electric Gun
(National Defense Industry Press
, Beijing
, 1995
), p. 94
(in Chinese).2.
A.
Larsson
, M.
Akyuz
, P.
Appelgren
, W.
Dingertz
, and T.
Hurtig
, “Modelling of a coilgun-based plate launcher for active armour applications
,” in 17th International Symposium on Electromagnetic Launch Technology
(2014
).3.
M. S.
Aubuchon
, T. R.
Lockner
, and B. N.
Turman
, “Results from sandia national laboratories/lockheed martin electromagnetic missile launcher (EMML)
,” in Pulsed Power Conference
(IEEE
, 2005
), pp. 75
–78
.4.
R.
Kaye
, B.
Turman
, M.
Aubuchon
et al., “Induction coilgun for EM mortar
,” in IEEE 34th International Conference on Plasma Science
(IEEE
, 2007
), pp. 1017
–1017
.5.
M. R.
Doyle
, D. J.
Samuel
, T.
Conway
, and R. R.
Klimowski
, “Electromagnetic aircraft launch system-EMALS
,” IEEE Trans. Magn.
31
(1
), 528
–533
(1995
).6.
E.
Inger
, “Electromagnetic launching systems to geosynchronously equatorial orbit in space and cost calculations
,” IEEE Trans. Plasma Sci.
45
(7
), 1663
–1666
(2017
).7.
T. G.
Engel
and M. A.
Prelas
, “Asteroid mining and deflection using electromagnetic launchers
,” IEEE Trans. Plasma Sci.
45
(7
), 1327
–1332
(2017
).8.
E.
Narevicius
, A.
Libson
, C. G.
Parthey
et al., “Stopping supersonic oxygen with a series of pulsed electromagnetic coils: A molecular coilgun
,” Phys. Rev. A
77
(5
), 2533
–2536
(2008
).9.
T. G.
Engel
, E. J.
Timpson
, and M. J.
Veracka
, “Demonstration of a reversible helical electromagnetic launcher and its use as an electronically programmable mechanical shock tester
,” IEEE Trans. Plasma Sci.
43
(5
), 1266
–1270
(2015
).10.
K.
Thom
, and J.
Norwood
, “Theory of electromagnetic accelerator for achieving hypervelocities
,” Technical Note D-886 (NASA
, Washington, DC, USA
, 1961
).11.
P.
Mongeau
, “Analysis of helical brush commutation
,” IEEE Trans. Magn.
20
(2
), 231
–234
(1984
).12.
W. R.
Snow
and R. L.
Willig
, “Design criteria for brush commutation high speed traveling wave coilguns
,” IEEE Trans. Magn.
27
(1
), 654
–659
(1991
).13.
T. G.
Engel
, W. C.
Nunnally
, and J. M.
Neri
, “Development of a medium-bore high-efficiency helical coil electromagnetic launcher
,” IEEE Trans. Plasma Sci.
32
(5
), 1893
–1895
(2004
).14.
W. C.
Nunnally
, S. M.
Huenefeldt
, and T. G.
Engel
, “Performance and scalability of MJ sequentially fired pulse forming networks for linear and nonlinear loads
,” IEEE Trans. Plasma Sci.
35
(2
), 484
–490
(2007
).15.
T. G.
Engel
and M. J.
Veracka
, “The voltage–current scaling relationship and impedance of DC electromagnetic launchers
,” IEEE Trans. Plasma Sci.
43
(5
), 1271
–1276
(2015
).16.
T. G.
Engel
, W. C.
Nunnally
, and J. M.
Neri
, “High-efficiency, medium-caliber helical coil electromagnetic launcher
,” IEEE Trans. Magn.
41
(11
), 4299
–4303
(2005
).17.
T. G.
Engel
, J. M.
Neri
, and M. J.
Veracka
, “Solid-projectile helical electromagnetic launcher
,” IEEE Trans. Plasma Sci.
37
(4
), 603
–607
(2009
).18.
P.
Mongeau
and F.
Williams
, “Helical rail glider launcher
,” IEEE Trans. Magn.
18
(1
), 190
–193
(1982
).19.
A.
Musolino
and R.
Rizzo
, “Numerical analysis of brush commutation in helical coil electromagnetic launchers
,” IET Sci. Meas. Technol.
5
(4
), 147
–154
(2011
).20.
D.
Yang
, T.
Shu
, Z.
Liu
, J.
Ouyang
, Z.
Shen
, and L.
Yang
, “Research on the commutation-induced voltage of helical coil electromagnetic launchers
,” IEEE Trans. Plasma Sci.
44
(6
), 991
–995
(2016
).21.
A.
Musolino
and R.
Rizzo
, “Numerical modeling of helical launchers
,” IEEE Trans. Plasma Sci.
39
(3
), 935
–940
(2011
).22.
T. G.
Engel
, J. M.
Neri
, and W. C.
Nunnally
, “Efficiency and scaling of constant inductance gradient DC electromagnetic launchers
,” IEEE Trans. Magn.
42
(8
), 2043
–2051
(2006
).23.
F. W.
Grover
, “Tables for the calculation of the inductance of circular coils of rectangular cross section
,” Sci. Pap. Bur. Stand.
18
(455
), 451
–487
(1921
).24.
T. G.
Engel
, D.
Surls
, and W. C.
Nunnally
, “Prediction and verification of electromagnetic forces in helical coil launchers
,” IEEE Trans. Magn.
39
(1
), 112
–115
(2003
).25.
L.
Shoubao
, R.
Jiangjun
, P.
Ying
, Z.
Yujiao
, and Z.
Yadong
, “Improvement of current filament method and its application in performance analysis of induction coil gun
,” IEEE Trans. Plasma Sci.
39
(1
), 382
–389
(2011
).26.
L.
Yao
, C.
Baichao
, Y.
Jiaxin
, and C.
Zihao
, “Mutual inductance calculations of inclined axial air-core circular coils with rectangular cross-sections
,” Trans. China Electrotech. Soc.
27
(5
), 132
–136
(2012
).27.
D.
Yang
, Z.
Liu
, and L.
Yang
, “Research on energy conversion efficiency of helical coil electromagnetic launcher
,” in IEEE International Symposium on Electromagnetic Launch Technology
(2014
).© 2018 Author(s).
2018
Author(s)
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