| Magnetic Flux Compression Simulations Using ALEGRA |
Jul 2012 |
18 pages |
| Authors:
Robert L Doney; Peter Bartkowski; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD WEAPONS AND MATERIALS RESEARCH DIRECTORATE
|
 | Magnetic flux compression (MFC) generators are pulsed-power devices that take a small electrical current and amplify it by exploiting the conservation of magnetic flux. Essentially, an explosive is used to compress an initial magnetic flux into a smaller volume, increasing the output current. The primary benefits of these devices are (1) the reduction in stored electrical energy and (2) obtaining very large currents or magnetic fields. For example, a capacitor ... |
|
| Vibration Energy Harvesting Concept using a Balanced Armature Transducer |
16 Apr 2012 |
30 pages |
| Authors:
Stephen C Thompson; PENNSYLVANIA STATE UNIV STATE COLLEGE APPLIED RESEARCH LAB
|
| Balanced armature transducers are used as the speakers in most hearing aids and in some small insert earphones. In this size range, the balanced armature speaker is a more efficient audio generator than other technologies. This project has investigated the possibility of using these same or similar balanced armature devices in a reciprocal configuration as the generator for vibration energy harvesting. Earlier work by Vitt [Nikolas T. Vitt, Investigation of ... |
|
| The Integration of YBCO Coated Conductors into Magnets and Rotating Machinery (Postprint) |
Feb 2012 |
9 pages |
| Authors:
G A Levin; P N Barnes; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH PROPULSION DIRECTORATE
|
| The implementation of the second generation high-Tc superconductors in power applications, such as electrical transformers, motors and generators requires superconducting wires that are superior to copper Litz wires at cryogenic temperatures in terms of losses in time-varying magnetic field, as well as in engineering current density. Another problem is to find a way to make practical coils and armatures out of flat tape-like conductors with low bending strain tolerance. We ... |
|
| Acceleration of an Initially Moving Projectile: Velocity-Injected Railguns and Their Effect on Pulsed Power |
Jul-2009 |
30 pages |
| Authors:
Del; Miguel Guercio; Alexander Zielinski; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD WEAPONS AND MATERIALS RESEARCH DIRECTORATE
|
| Calculations are performed for an initially moving projectile and a railgun. The initial velocity is provided by a 26-mm-diameter conventional propellant gun. A plasma armature is assumed for the railgun. The capacitor-based, pulsed power supply (PPS), located at barricade C, Aberdeen Proving Ground, MD, is assumed to provide the electrical energy for boosting the velocity to 2.5 km/s. Various scenarios are examined with respect to electrical pulse shape, the effect ... |
|
| Electromigration Related Effects At Metal-Metal Interfaces: Application To Railguns |
MAR 2007 |
75 pages |
| Authors:
Jr Cleveland William B.; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| This thesis had 2 objectives. The first purpose of this thesis was to develop an experimental procedure to study electric current induced flow of liquid metal, similar to that found at the armature-rail contact due to local melting, to determine the kinetics of liquid flow Ga under electric current conditions. For this, a model system comprising a bead of Ga on a Cu thin film track was devised in order ... |
|
| A First Report on Electromigration Studies at a Model Copper-Aluminum Railgun Contact |
DEC 2006 |
71 pages |
| Authors:
Luc D. Delaney; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF MECHANICAL AND ASTRONAUTICAL ENGINEERING
|
| The purpose of this thesis was to develop an experimental methodology to determine the effects of electromigration on the aluminum microstructure of the railgun armature. An experimental system which allowed simulation of an Al armature between two Cu rails with surface skins was devised. The system was designed small enough such that only small current ( |
|
| High-Efficiency Helical Coil Electromagnetic Launcher |
31 AUG 2006 |
37 pages |
| Authors:
Thomas G. Engel; William C. Nunnally; John M. Gahl; MISSOURI UNIV-COLUMBIA DEPT OF ELECTRICAL ENGINEERING
|
| Technical progress during the reporting period includes the development of new theory for electromagnetic launcher efficiency which is applicable to all constant inductance gradient launcher geometries. This theory also develops methods to predict the performance of different geometry electromagnetic launchers and compare them to each other. A theoretical analysis is also presented to design a helical electromagnetic launcher for a specific volt- amp characteristic. Experimentally measured performance is reported for ... |
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| Coefficient of Friction Measurement in the Presence of High Current Density |
MAY 2006 |
9 pages |
| Authors:
L. Brown; D. Xu; K. Ravi-Chandar; S. Satapathy; TEXAS UNIV AT AUSTIN INST FOR ADVANCED TECHNOLOGY
|
| On the micro-scale, armature rail interface contact is accomplished through surface asperity interaction. In this imperfect contact model (a version of the Bowden-Tabor model), we postulate the coexistence of one or more contact regimes, such as solid solid contact, liquid metal lubricated contact, and arcing contact. We are developing microscopic models and experimental apparatus to study this postulate. This work in particular describes the experimental apparatus developed to assist in ... |
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| Metallurgical Analysis of Railgun Material |
MAY 2006 |
11 pages |
| Authors:
Khershed P. Cooper; Harry N. Jones; Robert A. Meger; NAVAL RESEARCH LAB WASHINGTON DC MATERIAL SCIENCE AND TECHNOLOGY DIV
|
| The effect of number of shots on multiple launch railgun barrel material performance under significantly high current conditions was studied. Metallurgical analysis was conducted on rail samples from four sets of experiments involving increasing number of shots. Cross-sections of samples from two locations in the copper rail were examined using a variety of metallographic techniques. During each shot a thin film of molten aluminum from the armature deposited on the ... |
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| Design, Fabrication, and Testing of a Scalable Series Augmented Railgun Research Platform |
MAR 2006 |
135 pages |
| Authors:
Brian C. Black; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| The design and material properties of rails and projectiles are critical to the success of the Navy railgun. This thesis addresses the design, fabrication, and testing of a scalable square bore electromagnetic railgun. This railgun is designed to permit series augmented operation, and incorporates disposable rail liners to facilitate investigating the suitability of various rail materials. A series of shots has demonstrated performance consistent with theoretical modeling, including significant performance ... |
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| A Simple Transverse Motion Detector for Railguns |
JAN 2004 |
5 pages |
| Authors:
S. J. Levinson; Stephan Bless; TEXAS UNIV AT AUSTIN INST FOR ADVANCED TECHNOLOGY
|
| This paper addresses the accurate measurement of the transverse armature-sabot motion during a railgun shot. One way to make such measurements is to use three orthogonally arranged piezorestive accelerometers made by ENDEVCO. Model 7270A-200k is a tiny unit rated for measurements up to 200 kGee. Each unit costs about $ 1,500 and has a specified 4-kGee uncertainty due to "non-linearity and hysteresis" and a 5 percent "transverse sensitivity." There are ... |
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| An Investigation of Sliding Electrical Contact in Rail Guns and the Development of Grooved-Rail Liquid-Metal Interfaces |
DEC 2001 |
54 pages |
| Authors:
Mark T. Adamy; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| The barrel life of a solid armature rail gun is a critical issue, Arcing along the barrel pathway at the interfaces between the armature and the rails produces severe damage The ability to protect the rails and yet provide sufficient electrical contact to sustain arc-free high-current flow is desirable, This thesis investigates the use of liquid metal as an interface material between the sliding electrical contact surfaces of the armature ... |
|
| Current and Heat Transport in a Double Taper Sabot-Armature |
JUL 2001 |
31 pages |
| Authors:
John D. Powell; Alexander E. Zielinski; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD WEAPONS AND MATERIALS RESEARCH DIRECTORATE
|
| A model developed previously to investigate the transport of electromagnetic fields and energy in solid-armature rail guns is simplified to exclusively study heating within the interior of the armature. A particular type of armature is then specifically studied, and the effect of variation of a number of parameters that affect its geometry is investigated. Results of the calculations are studied carefully and explained by basic physical principles. Some indication of ... |
|
| Inductiveless Rail Launchers for Long Projectiles |
26 APR 2001 |
|
| Authors:
Yuri Dreizin; DREIZIN (YURI) MINNEAPOLIS MN
|
 | The paper presents rail launchers having substantially higher efficiency than railguns and much lower mechanical stresses in projectiles and launch tubes. Based on novel - inductiveless - architecture, which is especially effective for long projectiles, these launchers promise a number of weighty advantages such as: (1) Order of magnitude lower rail-to-rail repulsion, resulting in lightweight launch tubes; (2) No sabots, armature mass share only 25 - 35%; (3) Suppressed velocity ... |
|
| Investigation of Tungsten, Copper, and Silver Alloys with Indium at the Rail-Armature Interface on a Railgun Test Bench |
26 APR 2001 |
14 pages |
| Authors:
D. Gillich; W. Maier; MILITARY ACADEMY WEST POINT NY DEPT OFPHYSICS
|
| With the advent of electrically propelled ships, the Navy is now considering the use of electric power to launch projectiles in support of maritime land attack. Bore wear is one of the most significant challenges for a naval railgun program. The interface between the armature and rails is the most stressed point of a railgun because it transitions to liquid under high current densities. This liquid interface causes rail and ... |
|
| Investigating UHF Telemetry for Electromagnetic Launchers |
26 APR 2001 |
15 pages |
| Authors:
S. Levinson; L. Burke; M. Erengll; J. Faust; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| This paper describes an experimental investigation of the feasibility of microwave telemetry for conveying diagnostic information collected during and after launch from an electromagnetic (EM) gun. The study focused on extending the Hardened Subminiature Telemetry Sensor Systems (HSTSS) technology for use in EM launch environments. While HSTSS technology has already been successfully demonstrated in high-g, high-pressure launch environments in conventional gun systems, it has not yet been tested in an ... |
|
| Integrated Launch Package Design With Considerations for Reduced Scale Demonstration |
JAN 2001 |
37 pages |
| Authors:
Alexander E. Zielinski; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| The design of an integrated launch package for an electromagnetic rail gun is considered. A code that incorporates analytical engineering expressions for thermal and mechanical loads was used. The armature linear current density and armature and rail pressures are used to define the range of solutions, based on mission requirements and sub-projectile criteria. Characteristics for large and reduced scale launcher and integrated launch package (ILP) solutions are presented, which are ... |
|
| The Art of Bond Graph Construction for Transducers |
13 SEP 1999 |
|
| Authors:
Sam Hanish; NAVAL RESEARCH LAB WASHINGTON DC ACOUSTICS DIV
|
| The mathematical modeling of transducer by bond graphs possesses notable advantages. While these advantages come to true light in very complex devices, the method of bond graphs is applied here to elementary mechanical acoustic electrical devices, thus serving as an introduction to bond graph modeling procedures. The devices selected for illustration are: (1) the longitudinal vibrator, (2) the electrodynamic microphone, and (3) the moving armature transducer. In addition to these ... |
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| The Art of Bond Graph Construction for Transducers |
13 SEP 1999 |
27 pages |
| Authors:
Sam Hanish; NAVAL RESEARCH LAB WASHINGTON DC ACOUSTICS DIV
|
| The mathematical modeling of transducer by bond graphs possesses notable advantages. While these advantages come to true light in very complex devices, the method of bond graphs is applied here to elementary mechanical- acoustical-electrical devices, thus serving as an introduction to bond graph modeling procedures. The devices selected for illustration are: (1) the longitudinal vibrator, (2) the electrodynamic microphone, (3) the moving armature transducer. In addition to these examples, a ... |
|
| High Velocity Electromagnetic Mass Launcher Having an Ablation Resistant Insulator |
05 JAN 1999 |
|
| Authors:
Robert A. Meger; DEPARTMENT OF THE NAVY WASHINGTON DC
|
| A railgun having a composite insulator of laminated materials positioned between the rails. The composite insulator is comprised of a series of conducting layers oriented with the edges toward the bore, or barrel, of the railgun and their wide edges away from the bore. The laminate is layed lengthwise along the rails and is comprised of conducting layers of a high heat conductivity metal interleaved with an insulator material. The ... |
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| High Velocity Electromagnetic Mass Launcher Having an Ablation Resistant Insulator. |
01 DEC 1998 |
|
| Authors:
Robert A. Meger; DEPARTMENT OF THE NAVY WASHINGTON DC
|
| The invention pertains to a railgun having a composite insulator of laminated materials positioned between the rails. The composite insulator is comprised of a series of conducting layers oriented with the edges toward the bore, or barrel, of the railgun and their wide edges away from the bore. The laminate is layed lengthwise along the rails and is comprised of conducting layers of a high heat conductivity metal interleaved with ... |
|
| Transient Response of an Electromagnetic Rail Gun: A Pedagogical Model |
MAY 1998 |
30 pages |
| Authors:
Thomas B. Bahder; John D. Bruno; ARMY RESEARCH LAB ADELPHIA MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| We present a highly simplified model of an electromagnetic rail gun. The energy source for the gun consists of a rotating magnetic dipole moment positioned at the center of a stator coil. The dipole moment is free to rotate about an axis normal to the stator coil's axis, inducing a current in the rail gun stator circuit, and thereby propelling the projectile. The system's dynamical behavior is described by three ... |
|
| A Preliminary Study of Wear in the Solid-Armature Railgun |
DEC 1997 |
51 pages |
| Authors:
J. Powell; A. Zielinski; TEXAS UNIV AT AUSTIN INST FOR ADVANCED TECHNOLOGY
|
| A model previously developed to investigate current and heat transport in solid-armature railguns is extended. The 2-dimensional model involves the numerical solution of coupled Maxwell and heat-transport equations in both the armature and rails of the railgun. The principal extensions include the development of a general transformation which maps an armature of fairly arbitrary shape into a rectangular computational region, and the inclusion of melting within the appropriate governing equations. ... |
|
| Analysis of the Armature-Rail Interface in Solid Armature Railguns: Collected Reports of Professor L. C. Woods Volume II (November 1996 - May 1997) |
AUG 97 |
49 pages |
| Authors:
L. C. Woods; TEXAS UNIV AT AUSTIN INST FOR ADVANCED TECHNOLOGY
|
| A second collection of reports written by L.C. Woods for the Institute for Advanced Technology (IAT), University of Texas at Austin, investigating the liquid metal interface between a solid armature and conducting rail of an electromagnetic launcher. The first report has multiple objectives: determine the rate at which the armature is melted by viscosity to find the thickness of the deposited layer of aluminum; investigate the stability of the liquid ... |
|
| 6TH European Symposium on Electromagnetic Launch Technology, The Hague, 25-28 May 1997. Proceedings |
03 JUN 97 |
|
| Authors:
PRINS MAURITS LABORATORIUM TNO RIJSWIJK (NETHERLANDS)
|
| The Final Proceedings for 6th European Symposium on Electromagnetic Launch Technology, 25 May 1997 - 28 May 1997. The Topics covered include: Pulsed power supplies, accelerators and projectiles and systems. |
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| An Investigation of the Ballistic Performance for an Electromagnetic Gun-Launched Projectile |
JUN 97 |
66 pages |
| Authors:
Alexander E. Zielinski; Paul Weinacht; David W. Webb; Keith P. Soencksen; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| The Cannon-Caliber Electromagnetic Gun (CCEMG) Program is a major effort toward proving the viability of electromagnetic (EM) weapons for future use by the armed services. Crucial to the success of the program are the operational characteristics of the launcher and the integrated launch package (ILP), which consists of an armature/sabot and a subprojectile. To date, 39 shots have been fired at the U.S. Army Research Laboratory (ARL) using a 1.6-MJ ... |
|
| Analysis of the Armature-Rail Interface in Solid Armature Railguns: Collected Reports of Professor L. C. Woods (October 1995-June 1996) |
AUG 96 |
75 pages |
| Authors:
L. C. Woods; TEXAS UNIV AT AUSTIN INST FOR ADVANCED TECHNOLOGY
|
| A collection of reports written by L.C. Woods for the institute for Advanced Technology (lAT), University of Texas at Austin, investigating the liquid metal interface between a solid armature and conducting rail of an electromagnetic launcher as it effects transition and gouging. In the first report, a two dimensional current melt wave model is presented that provides a datum against which observations and numerical modeling can be compared. The second ... |
|
| Design and Construction of a One Meter Electromagnetic Railgun |
JUN 96 |
59 pages |
| Authors:
Fred C. Beach; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| The acceleration of projectiles through the use of electromagnetic forces (Railguns) has many advantages over conventional methods. Foremost are the higher velocities which can be achieved and the reduction in firing platform sesitivity to hits. Projectile velocities on the order of 3-4 kilometers per second allow the use of 'kinetic energy kill' projectiles which are effectively inert munitions. Additionally, by using purely electromotive force for the acceleration, the need for ... |
|
| Railgun Plasma Armatures |
APR 96 |
152 pages |
| Authors:
Dennis Keefer; Roger Crawford; Monty Smith; Jamie Taylor; Dmitri Kondrashov; TENNESSEE UNIV SPACE INST TULLAHOMA CENTER FOR LASER APPLICATIONS
|
|
| Commissioning Tests of the Medium Caliber Railgun Launcher |
MAR 96 |
51 pages |
| Authors:
Keith A. Jamison; TEXAS UNIV AT AUSTIN INST FOR ADVANCED TECHNOLOGY
|
| Checkout tests and initial test firings of the IAT-HVL, seven meter long, 40 mm square-bore railgun were conducted in October 1995. This report details the initial performance of the Medium Caliber Launcher (MCL) and gives performance data for a simple 'C' shaped solid armature. The commissioning tests in-dude electrical data from tests with a fixed shorting block at the muzzle and very low energy tests for armature friction where the ... |
|
| Cryogenic Aluminum Armature Bar for High Power Generators |
AUG 1995 |
99 pages |
| Authors:
Lidia Chubraeva; INSTITUTE FOR ELECTROTECHNICAL PROBLEMSST PETERSBURG (RUSSIA)
|
| To improve the design of light-weight cryogenic alternator it is necessary to pay extreme attention not only to the design of the rotor, but to the stator design as well. Main elements of the stator are: the three-phase armature winding and the outer screen, which protects the alternator exterior from the magnetic flux, induced inside, and the alternator interior from the outside stray magnetic fields. ... |
|
| Current and Heat Transport in the Cannon-Caliber Electromagnetic Gun Armature |
AUG 95 |
33 pages |
| Authors:
John D. Powell; Alexander E. Zielinski; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| A numerical model which we previously developed is extended and used to solve the equations which predict current and heat transport in a series- augmented, solid-armature railgun. The model is two-dimensional and fully time dependent. Specific calculations are carried out to analyze the armature recently designed and developed in the Cannon-Caliber Electromagnetic Launcher (CCEML) Program. The most extensive computations are for a situation in which the projectile is started at ... |
|
| Design of a Fast-Tool Servo System Using Magnetic Servo Levitation |
15 JAN 95 |
33 pages |
| Authors:
Paul I. Ro; NORTH CAROLINA STATE UNIV AT RALEIGH PRECISION ENGINEERING CENTER
|
| Magnetic Servo Levitation is proposed as a method to drive a Fast Tool Servo System, in order to compensate for errors resulting from mechanical misalignment, slide vibration, tool wear, and cutting dynamics on a Diamond Turning Machine. Theoretical magnetic equations have provided a basis for electromagnet design. Further analyses have used finite element models to find trends in magnetic properties, as well as assisting in structural design. A T- shaped, ... |
|
| Terminal Ballistic Evaluation of a Candidate 0.60-Caliber Electromagnetically Launched Long-Rod Penetrator |
SEP 93 |
70 pages |
| Authors:
Timothy G. Farrand; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| A candidate 0.60-cal. armor-piercing, fin-stabilized, discarding armature, kinetic energy penetrator, to be fired from an electromagnetic (EM) launcher, was evaluated for its terminal ballistic performance against rolled homogeneous armor (RHA). A limited data set was also generated for high hardness armor. The candidate design is similar to one generated from an empirically based optimization study. The study considered launch, flight, and terminal ballistic performance from a 0.60-cal. electromagnetic gun. Projected ... |
|
| Integrated Fundamental Research on Current Collection |
JUN 93 |
53 pages |
| Authors:
Doris Kuhlmann-Wilsdorf; Leo Tran; VIRGINIA UNIV CHARLOTTESVILLE SCHOOL OF ENGINEERING AND APPLIED SCIENCE
|
| The aim of our research was to add to the basic understanding in the area of current collection with particular emphasis on topics likely to benefit practical objectives. Under sponsorship of this contract, 23 papers were published in the international literature. Additionally, 13 invited lectures and 11 contributed lectures on various aspects of this research were delivered at universities, research laboratories, and international conferences by the principal investigator and coworkers. ... |
|
| Two-Dimensional Model for Current and Heat Transport in Solid-Armature Railguns |
FEB 93 |
34 pages |
| Authors:
John D. Powell; David J. Walbert; Alexander E. Zielinski; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| A numerical model is developed for solving the equations which predict current and heat transport in a solid-armature railgun. The model is two dimensional and fully time dependent. Some preliminary calculations are carried out for a 'U-shaped' armature similar to that currently under investigation in the ARDEC small and cannon-caliber railgun programs. The most extensive calculations are for a situation in which the projectile is started at rest and accelerated ... |
|
| A Multiple Armature Railgun Launcher |
JAN 93 |
12 pages |
| Authors:
Mark W. Heyse; Antonios Challita; Brian L. Maas; David P. Bauer; IAP RESEARCH INC DAYTON OH
|
| As longer projectiles are accelerated. the efficiency (projectile mass/launch mass) of the launch package decreases. The reduction in efficiency makes launching projectiles with a L/D (length-to-diameter ratio) greater than 20 undesirable. EM guns have several launch characteristics that differ from conventional guns. Higher launch velocities are achievable in EM guns because sonic gas velocities do not limit the projectile velocity. Acceleration profiles for EM guns are more constant. The acceleration ... |
|
| Railgun Armature Velocity Improvement SBIR Phase 2 |
AUG 92 |
71 pages |
| Authors:
Leo E. Thurmond; David P. Bauer; IAP RESEARCH INC DAYTON OH
|
| Railgun hypervelocity performance has not been repeatably demonstrated at velocities over 6 km/s. A significant performance limiting phenomena is the formation of secondary current paths in parallel with the main projectile accelerating plasma. A confined plasma armature technique was developed to prevent secondary armature formation. Confinement prevents loss of ionized material from the plasma armature and thereby prevents formation of a low rail-to-rail conductance. We controlled pressure in the confined ... |
|
| Validation of the Flux Loop Diagnostic for the Measurement of Launch Package Motion during Electromagnetic Launch |
JUL 92 |
|
| Authors:
M. Koops; PRINS MAURITS LABORATORIUM TNO RIJSWIJK (NETHERLANDS)
|
| The development of diagnostics for studying the behaviour and performance of armatures and rail accelerators is one of the subjects covered by the section EML-research of the PML-Pulse Physics Laboratory. Within that framework the development of data analysis software is in progress. This report describes a new data reduction technique to resolve armature motion from the measurement of the voltage induced in a flux loop diagnostic and the load current ... |
|
| United States Air Force Graduate Student Research Program for 1990. Program Technical Report. Volume 3 |
05 JUN 91 |
410 pages |
| Authors:
Rodney Darrah; UNIVERSAL ENERGY SYSTEMS INC DAYTON OH
|
| The United States Air Force Graduate Student Research Program (USAF- GSRP) is conducted under the United Air Force Summer Faculty Research Program. This report includes the following topics: Two Dimensional Simulation of Railgun Plasma Armatures; Infrared Laser Polarimetry; Computing Circumcenters; High Speed Video Systems for Munitions Testing; Physical Aspects of the Penetration of Reinforced Concrete Slabs; High Speed Parallel Signal Processing; Graphics for Turbine Math Models; A Neural Network for ... |
|
| Rail Circuit Augmentation |
MAY 91 |
19 pages |
| Authors:
William H. Davis; ARMY ARMAMENT RESEARCH DEVELOPMENT AND ENGINEERING CENTER PICATINNY ARSENAL N J FIRE SUPPORT ARMAMENT CENTER
|
| A concept for an augmented railgun barrel and integrated projectile/ armature system is presented. The system makes use of the rail geometry to expose the augmenting rails to the bore, and incorporates dual tandem armatures in the launch package. Benefits include reduced current and power required to launch a given mass and a modest reduction in sabot mass due to creation of multiple tension and compression regions resulting from the ... |
|
| Plasma Analysis of a Small-Bore, Arc-Armature Railgun |
NOV 90 |
37 pages |
| Authors:
Alexander E. Zielinski; John D. Powell; ARMY BALLISTIC RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| Diagnostic measurements of plasma-armature properties have been made on a 9.3-mm square-bore, arc-driven railgun. The measurements include the total current carried by the arc, the voltages across the breech and muzzle ends of the gun tube, light output from the arc seen at points along the gun tube, and finally the time rate of change of the induction field associated with the armature current. From these data it is possible ... |
|
| Application of a Rechargeable, Small Caliber Railgun Power Supply |
JUL 90 |
36 pages |
| Authors:
Alexander E. Zielinski; ARMY BALLISTIC RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| A capacitive power supply for driving a railgun load has been developed using solid-state switch gear and electrolytic capacitors. Electrolytic capacitors and solid-state switching devices allow relative ease of component orientation and insensitivity to field conditions. The circuit is constructed such that half the bank capacitance is initially charged while the other half is uncharged. Both halves are connected in series with the load. When the discharge is initiated, the ... |
|
| Laser Controlled Semiconductor Armature for Electromagnetic Launchers. |
16 JAN 1990 |
|
| Authors:
Louis J. Jasper Jr.; Maurice Weiner; Lawrence J. Bovino; DEPARTMENT OF THE AIR FORCE WASHINGTON DC
|
| An electromagnetic launcher or railgun includes a projectile or armature which is comprised of an optically activated semiconductor switch device including a body of bulk semiconductor material, such as gallium arsenide (GaAs) or gallium arsenide doped with chromium (Cr: GaAs), located between a pair of rails across which is connected a relatively high current source. A source of optical energy, such as a pulsed laser, directs optical energy to at ... |
|
| ARDEC (Armament Research, Development and Engineering Center) Electric Gun In-House Test Program - Fiscal Year 1988 |
JAN 90 |
53 pages |
| Authors:
Curtis Dunham; Thomas Coradeschi; Duk I. Chang; Kenneth Van Camp; Gregory Colombo; ARMY ARMAMENT RESEARCH DEVELOPMENT AND ENGINEERING CENTER DOVER NJ FIRE SUPPO RT ARMAMENT CENTER
|
| This report summarizes the experimental testing conducted on three railguns. It discusses improvements to the 30-megajoule homopolar generator and 250-kilojoule capacitor bank as well as instrumentation techniques and analysis capabilities. It also describes the planned high energy lab. The 50-mm square bore railgun demonstrated dramatic improvements in barrel wear with solid armatures of proper design. Tests on the short prototype of the 20-mm round bore railgun indicated that the composite ... |
|
| Theoretical Modeling of Accelerating Arc Plasmas |
22 APR 88 |
|
| Authors:
Manuel A. Huerta; MIAMI UNIV CORAL GABLES FLA
|
| The researchers present a calculation in a simplified geometry for the current distribution in the rails, taking into account the motion of the armature and the time variation of the current. Closed form, asymptotic, results for the current density are obtained for arbitrary time dependent electrical conductivity of the rails, and v is the speed of the armature. Because of eddy current effects the rail current may reverse in portions ... |
|
| Polarized Rotary Solenoid. |
05 APR 1988 |
|
| Authors:
George E. Cooksey; DEPARTMENT OF THE NAVY WASHINGTON DC
|
| A rotary solenoid providing opposite direction pivoting movement on opposite polarity d.c. energization. The solenoid has a pivoting shaft from which a permanent magnet armature having ends of opposite magnetic polarity extends transversely and oppositely. The armature is disposed between a pair of pole pieces each of which extends along the armature between its ends. The pole pieces are oppositely electromagnetically magnetized by a d.c. winding so that reversing the ... |
|
| Rail Damage in a Solid Armature Rail Gun |
DEC 87 |
22 pages |
| Authors:
Theresa Brassard; Clarke G. Homan; ARMY ARMAMENT RESEARCH, DEVELOPMENT AND ENGINEERING CENTER WATERVLIET NY BENE T WEAPONS LAB
|
| Plasma arc drive rail guns operate by forming a high temperature plasma behind the projectile using a thin metal fuze. These systems achieve the highest projectile velocities (about 12 km /sec), since the driving force includes a substantial plasma pressure as well as the electromagnetic or Lorentz force. Unfortunately, severe rail damage occurs primarily from the intense temperatures generated by the plasma arc and the wiping motion of the armature ... |
|
| Analysis of a Series of Electromagnetic Launcher Firings |
JUN 87 |
|
| Authors:
V. Kowalenko; MATERIALS RESEARCH LABS ASCOT VALE (AUSTRALIA)
|
| In this report theoretical aspects of electromagnetic launchers are presented in conjunction with an analysis of diagnostic measurements taken during the RAPIS Plasma Intensity Profiles (RPIP) series of firings. These theoretical aspects deal with the current-time behaviour, the plasma temperature and the evaluation of railgun parameters such as the efficiency and effective inductance per unit length. The principal aims of the RPIP series were: (1) to see if different types ... |
|
| A Laboratory Railgun for Terminal Ballistics and Arc Armature Research Studies |
JUN 87 |
59 pages |
| Authors:
Daniel L. Vrable; Stuart N. Rosenwasser; Kenneth J. Cheverton; SPARTA INC DEL MAR CA
|
| A conceptual design was developed for a laboratory railgun suitable for both rac armature research and terminal ballistics studies. High utility and easy maintenance were the key design considerations. Parametric trade-off studies were conducted to evaluate and select the railgun parameters to achieve a system that accelerate a 120 gm launch package to 2 km/s. The design incorporates use of advanced materials for the bore components to minimize maintenance, and ... |
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Reports by Keyword(s)
ARMATURES
