scholarly journals Inductance Gradient Calculations of EMFY-3 Electromagnetic Launcher

2021 ◽  
Author(s):  
Nail Tosun ◽  
Ozan Keysan
Keyword(s):  
Doppler Radar ◽  
Slight Variation ◽  
Input Energy ◽  
Linear Current ◽  
Electromagnetic Launch ◽  
Electromagnetic Launcher ◽  
Breaking Mechanism ◽  
Muzzle Energy ◽  
Current Densities ◽  
Electromagnetic Calculations

<div>ASELSAN Inc. has been working on electromagnetic launch technologies since 2014. The first prototype, EMFY-1, has a 25 mm × 25 mm square bore and 3-m-length rails. The second prototype, EMFY-2, has a 50 × 50 mm square bore and 3-m-length. In this paper, a recently developed prototype, EMFY-3, is presented, which has a 50 × 75 mm rectangular bore and 6-m-length. The input energy of the PPS is doubled to 8 MJ, and the 2.91 MJ muzzle energy is obtained up to now. Rail currents, breech, and muzzle voltages are measured to investigate electromagnetic calculations. Velocity curves are captured with Doppler radar, which enables us to establish propulsive inductance gradient L0pr transients empirically. The results confirm that L0 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 from one launch to another with different rails’ current magnitudes. The transition phenomenon is a candidate for the drop in the L0 pr, as it occurs more likely at launches with higher linear current densities.</div>

scholarly journals Inductance Gradient Calculations of EMFY-3 Electromagnetic Launcher

2021 ◽  
Author(s):  
Nail Tosun ◽  
Ozan Keysan
Keyword(s):  
Doppler Radar ◽  
Slight Variation ◽  
Input Energy ◽  
Linear Current ◽  
Electromagnetic Launch ◽  
Electromagnetic Launcher ◽  
Breaking Mechanism ◽  
Muzzle Energy ◽  
Current Densities ◽  
Electromagnetic Calculations

<div>ASELSAN Inc. has been working on electromagnetic launch technologies since 2014. The first prototype, EMFY-1, has a 25 mm × 25 mm square bore and 3-m-length rails. The second prototype, EMFY-2, has a 50 × 50 mm square bore and 3-m-length. In this paper, a recently developed prototype, EMFY-3, is presented, which has a 50 × 75 mm rectangular bore and 6-m-length. The input energy of the PPS is doubled to 8 MJ, and the 2.91 MJ muzzle energy is obtained up to now. Rail currents, breech, and muzzle voltages are measured to investigate electromagnetic calculations. Velocity curves are captured with Doppler radar, which enables us to establish propulsive inductance gradient L0pr transients empirically. The results confirm that L0 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 from one launch to another with different rails’ current magnitudes. The transition phenomenon is a candidate for the drop in the L0 pr, as it occurs more likely at launches with higher linear current densities.</div>

Electromagnetic-launch-based method for cost-efficient space debris removal

2020 ◽  
Vol 29 (1) ◽  
pp. 94-106
Author(s):  
Chongyuan Hou ◽  
Yuan Yang ◽  
Yikang Yang ◽  
Kaizhong Yang ◽  
Xiao Zhang ◽  
...  
Keyword(s):  
Space Debris ◽  
Orbit Space ◽  
Low Earth Orbit ◽  
Research Progress ◽  
Area Of Interest ◽  
Electromagnetic Launch ◽  
Debris Removal ◽  
Significant Research ◽  
Electromagnetic Launcher ◽  
Cost Efficient

AbstractThe increase in space debris orbiting Earth is a critical problem for future space missions. Space debris removal has thus become an area of interest, and significant research progress is being made in this field. However, the exorbitant cost of space debris removal missions is a major concern for commercial space companies. We therefore propose the debris removal using electromagnetic launcher (DREL) system, a ground-based electromagnetic launch system (railgun), for space debris removal missions. The DREL system has three components: a ground-based electromagnetic launcher (GEML), suborbital vehicle (SOV), and mass of micrometer-scale dust (MSD) particles. The average cost of removing a piece of low-earth orbit space debris using DREL was found to be approximately USD 160,000. The DREL method is thus shown to be economical; the total cost to remove more than 2,000 pieces of debris in a cluster was only approximately USD 400 million, compared to the millions of dollars required to remove just one or two pieces of debris using a conventional space debris removal mission. By using DREL, the cost of entering space is negligible, thereby enabling countries to remove their space debris in an affordable manner.

scholarly journals Bus Impact on the Inductance Distribution of Electromagnetic Launchers

2021 ◽  
Author(s):  
Nail Tosun ◽  
Ozan Keysan
Keyword(s):  
Simulation Models ◽  
Careful Examination ◽  
Physical Conditions ◽  
Electromagnetic Launchers ◽  
Electromagnetic Launcher ◽  
Bus Structure ◽  
Electromagnetic Calculations ◽  
Operation Risk ◽  
Current Transients ◽  
Good Agreement

<div>Simulations are crucial in the electromagnetic launcher (EML) researches on account of extreme physical conditions. More energy into the system adds weight to the model’s accuracy as the operation risk rises. In this paper, the electromagnetic impact of the bus structure is discovered in a recently developed EMFY-3 electromagnetic launcher, is presented. An H-shaped bus structure is used for current injection. However, experiments showed that the H-shaped bus changes inductance calculations. A careful examination is made to reveal the physical reasoning of the bus impact. We hypothesize that the rail portion surrounded with bus geometry has less inductance than the rest due to the eddy current created by rail current transients, which should be calculated carefully through numerical calculations, i.e., 3-D Finite Element Method (FEM). Two different simulation models were constructed to test the hypothesis. Moreover, rail currents, breech, and muzzle voltages are measured to investigate electromagnetic calculations. Results showed a good agreement with experiments where the bus structure was modeled explicitly. That aspect showed that the bus structure should be well-examined when multiple PPS are connected.</div>

scholarly journals Electromagnetic launch systems for civil aircraft assisted take-off

2015 ◽  
Vol 64 (4) ◽  
pp. 535-546 ◽  
Author(s):  
Luca Bertola ◽  
Tom Cox ◽  
Patrick Wheeler ◽  
Seamus Garvey ◽  
Herve Morvan
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Linear Motor ◽  
Element Analysis ◽  
Engine Thrust ◽  
Electromagnetic Launch ◽  
Civil Aircraft ◽  
Electromagnetic Launcher ◽  
Initial Acceleration ◽  
Launch Systems

Abstract This paper considers the feasibility of different technologies for an electromagnetic launcher to assist civil aircraft take-off. This method is investigated to reduce the power required from the engines during initial acceleration. Assisted launch has the potential of reducing the required runway length, reducing noise near airports and improving overall aircraft efficiency through reducing engine thrust requirements. The research compares two possible linear motor topologies which may be efficaciously used for this application. The comparison is made on results from both analytical and finite element analysis (FEA).

Stress Analysis of Rail for an Electromagnetic Launcher due to Projectile Movement

2011 ◽  
Vol 199-200 ◽  
pp. 603-608
Author(s):  
Yan Bo Geng ◽  
Li Zhong Xu
Keyword(s):  
Mechanical Properties ◽  
Stress Distribution ◽  
Stress Analysis ◽  
Calculated Result ◽  
Theoretical Basis ◽  
Superposition Principle ◽  
Bending Stress ◽  
Electromagnetic Launch ◽  
Electromagnetic Launcher ◽  
Electromagnetic Pressure

The principle of electromagnetic launch is introduced. The equation of electromagnetic load applied on rails is given. Based on the calculated result of electromagnetic pressure, the equation for calculating bending stress of rail on the elastic foundation is deduced using superposition principle. The stress distribution in rail with the armature in different positions is analyzed. Compared with results considering the force on the rail as uniformed load, the calculating results of stress distribution are more accuracy and useful for intensity and rigidity design of electromagnetic launch. The study may provide a theoretical basis for further analysis of systemic mechanical properties.

Analysis of the magnetic field and electromagnetic force of a non-striking weft insertion system for super broad-width looms, based on an electromagnetic launcher

2019 ◽  
Vol 89 (21-22) ◽  
pp. 4620-4631
Author(s):  
Xu Qiao ◽  
Mei Shunqi ◽  
Yan Xiaoyu ◽  
Md Mazharul Islam ◽  
Chen Zhen ◽  
...  
Keyword(s):  
Finite Element ◽  
Electromagnetic Field ◽  
Electromagnetic Force ◽  
Electromagnetic Launch ◽  
Insertion Method ◽  
Electromagnetic Launcher ◽  
Insertion Mechanism ◽  
Numerical Finite Element ◽  
Comparison Of The Results ◽  
Work Done

Weft insertion based on electromagnetic launch technology is a novel and very promising approach for super broad-width (6–12 m) (SBW) looms. There are considerable challenges involved in designing such a system, including analyzing the electromagnetic field while incorporating the effect of a clip weft device, and accurately calculating the electromagnetic and motion parameters of the weft insertion mechanism. In this study, an electromagnetic launch, non-striking weft insertion method for an SBW loom is proposed. The electromagnetic field is analyzed with the finite element method and includes the effect of a clip weft device. Simulation of the motion, analysis of the maximum flight speed of the clip weft device and the work done by electromagnetic force are presented. We also describe an experimental model for electromagnetic launch weft insertion and calculate the electromagnetic force required for weft insertion, using analytical methods and numerical finite element methods. Comparison of the results with measured values shows that this electromagnetic launch weft insertion system has good flexibility. In addition, the weft insertion speed required for different width looms can be obtained by changing the current of the coil or the coil stage number of the launching system.

scholarly journals Bus Impact on the Inductance Distribution of Electromagnetic Launchers

2021 ◽  
Author(s):  
Nail Tosun ◽  
Ozan Keysan
Keyword(s):  
Simulation Models ◽  
Careful Examination ◽  
Physical Conditions ◽  
Electromagnetic Launchers ◽  
Electromagnetic Launcher ◽  
Bus Structure ◽  
Electromagnetic Calculations ◽  
Operation Risk ◽  
Current Transients ◽  
Good Agreement

<div>Simulations are crucial in the electromagnetic launcher (EML) researches on account of extreme physical conditions. More energy into the system adds weight to the model’s accuracy as the operation risk rises. In this paper, the electromagnetic impact of the bus structure is discovered in a recently developed EMFY-3 electromagnetic launcher, is presented. An H-shaped bus structure is used for current injection. However, experiments showed that the H-shaped bus changes inductance calculations. A careful examination is made to reveal the physical reasoning of the bus impact. We hypothesize that the rail portion surrounded with bus geometry has less inductance than the rest due to the eddy current created by rail current transients, which should be calculated carefully through numerical calculations, i.e., 3-D Finite Element Method (FEM). Two different simulation models were constructed to test the hypothesis. Moreover, rail currents, breech, and muzzle voltages are measured to investigate electromagnetic calculations. Results showed a good agreement with experiments where the bus structure was modeled explicitly. That aspect showed that the bus structure should be well-examined when multiple PPS are connected.</div>

A Stable Field Emission Electron Source

1977 ◽  
Vol 35 ◽  
pp. 58-59
Author(s):  
W.R. Bottoms ◽  
G.B. Haydon
Keyword(s):  
Field Emission ◽  
Signal To Noise Ratio ◽  
High Brightness ◽  
Electron Sources ◽  
Brightness Field ◽  
Current Densities ◽  
Properties Of Materials ◽  
Stable Field ◽  
Stable Current ◽  
Careful Design

There is great interest in improving the brightness of electron sources and therefore the ability of electron optical instrumentation to probe the properties of materials. Extensive work by Dr. Crew and others has provided extremely high brightness sources for certain kinds of analytical problems but which pose serious difficulties in other problems. These sources cannot survive in conventional system vacuums. If one wishes to gather information from the other signal channels activated by electron beam bombardment it is necessary to provide sufficient current to allow an acceptable signal-to-noise ratio. It is possible through careful design to provide a high brightness field emission source which has the capability of providing high currents as well as high current densities to a specimen. In this paper we describe an electrode to provide long-lived stable current in field emission sources.The source geometry was based upon the results of extensive computer modeling. The design attempted to maximize the total current available at a specimen.

A new type of defect structure in 124-superconducting oxide revealed by HREM

1991 ◽  
Vol 49 ◽  
pp. 1092-1093
Author(s):  
R. Sharma ◽  
B.L. Ramakrishna ◽  
N.N. Thadhani ◽  
D. Hianes ◽  
Z. Iqbal
Keyword(s):  
Shock Wave ◽  
Defect Structure ◽  
Neutron Radiation ◽  
Weak Links ◽  
Defect Structures ◽  
New Materials ◽  
New Type ◽  
Current Densities ◽  
Processing Techniques ◽  
Microstructural Studies

After materials with superconducting temperatures higher than liquid nitrogen have been prepared, more emphasis has been on increasing the current densities (Jc) of high Tc superconductors than finding new materials with higher transition temperatures. Different processing techniques i.e thin films, shock wave processing, neutron radiation etc. have been applied in order to increase Jc. Microstructural studies of compounds thus prepared have shown either a decrease in gram boundaries that act as weak-links or increase in defect structure that act as flux-pinning centers. We have studied shock wave synthesized Tl-Ba-Cu-O and shock wave processed Y-123 superconductors with somewhat different properties compared to those prepared by solid-state reaction. Here we report the defect structures observed in the shock-processed Y-124 superconductors.

Study of segregation in La1.8Sr0.2CuO4 superconductor by STEM-EDS microanalysis

1987 ◽  
Vol 45 ◽  
pp. 54-55
Author(s):  
T. F. Kelly ◽  
P. J. Lee ◽  
E. E. Hellstrom ◽  
D. C. Larbalestier
Keyword(s):  
Rare Earth ◽  
High Field ◽  
Transport Current ◽  
Total Thickness ◽  
New Class ◽  
Ceramic Superconductors ◽  
Current Densities ◽  
Group Ii ◽  
Eds Microanalysis

Recently there has been much excitement over a new class of high Tc (>30 K) ceramic superconductors of the form A1-xBxCuO4-x, where A is a rare earth and B is from Group II. Unfortunately these materials have only been able to support small transport current densities 1-10 A/cm2. It is very desirable to increase these values by 2 to 3 orders of magnitude for useful high field applications. The reason for these small transport currents is as yet unknown. Evidence has, however, been presented for superconducting clusters on a 50-100 nm scale and on a 1-3 μm scale. We therefore planned a detailed TEM and STEM microanalysis study in order to see whether any evidence for the clusters could be seen.A La1.8Sr0.2Cu04 pellet was cut into 1 mm thick slices from which 3 mm discs were cut. The discs were subsequently mechanically ground to 100 μm total thickness and dimpled to 20 μm thickness at the center.

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