Download or read book Rail Erosion and Projectile Diagnostics for an Electro Magnetic Gun written by William E. Culpeper and published by . This book was released on 2002-06-01 with total page 65 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rail guns will not be introduced to the Navy until there is a means of limiting rail erosion. Erosion occurs when a sliding contact loses electrical contact with the rails. Research for this thesis was centered on combating the rail erosion problem and developing a way to record the voltage drop across the rails of the Naval Post Graduate School's 4-inch Electro-Magnetic Gun. A laser was also added to the rail gun so that the projectile's velocity could be recorded as it exits the gun's barrel. Silver paste was used to coat the grooved rails, thereby establishing a strong electrical contact between the rails and projectile. Results indicate that silver paste limits erosion inflicted on both the rails and projectile, by increasing the electrical contact at the rail- projectile interface. Consistent measurements of the projectile's velocity were also obtained.
Download or read book Critical Velocity of Electromagnetic Rail Gun in Response to Projectile Movement written by and published by . This book was released on 2002 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: A model is developed to investigate file dynamic response of an electromagnetic rail gun induced by a moving magnetic pressure during launch of projectiles. As the projectile velocity approaches a critical value, resonance can occur and cause high-amplitude stress and strain in the rail at the instant and location of the projectile's passage. In this study, governing equations of a railgun under dynamic-loading conditions are derived that illustrate a lower-bound critical velocity in terms of material properties, geometry, and barrel cross section. A study is then performed to show the effect of these parameters on the critical velocity of the barrel. Accordingly, the model that accounts for projectile velocity and gun construction can be used to guide barrel design.
Download or read book Critical Velocity of Electromagnetic Rail Gun in Response to Projectile Movement written by Jerome T. Tzeng and published by . This book was released on 2002 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: A model is developed to investigate file dynamic response of an electromagnetic rail gun induced by a moving magnetic pressure during launch of projectiles. As the projectile velocity approaches a critical value, resonance can occur and cause high-amplitude stress and strain in the rail at the instant and location of the projectile's passage. In this study, governing equations of a railgun under dynamic-loading conditions are derived that illustrate a lower-bound critical velocity in terms of material properties, geometry, and barrel cross section. A study is then performed to show the effect of these parameters on the critical velocity of the barrel. Accordingly, the model that accounts for projectile velocity and gun construction can be used to guide barrel design.
Download or read book Megagauss Magnetic Field Generation Its Application to Science and Ultra high Pulsed power Technology written by Hans J. Schneider-Muntau and published by World Scientific. This book was released on 2004 with total page 749 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Megagauss VIII was held in connection with the conference "Physical Phenomena at High Magnetic Fields - III" (PPHMF-III) in order to encourage and facilitate cross-links between the two scientific communities"--p. xiii.
Download or read book Critical Velocity of Electromagnetic Gun in Response to Projectile Movement written by Jerome T. Tzeng and published by . This book was released on 2001 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: A model is developed to investigate the dynamic response of an electromagnetic (EM) rail gun, induced by a moving magnetic pressure during launch of projectiles. As the projectile velocity approaches a critical value, resonance can occur and cause high amplitude stress and strain in the rail at the instant and location of projectile's passage. In this study, governing equations of a railgun under dynamic loading conditions are derived that illustrate a lower-bound critical velocity in terms of material properties, geometry, and barrel cross-section. That represents the worst case or a lower bound solution for the structure under a dynamic loading condition. A study is then performed to show the effect of these parameters on the critical velocity of the barrel. Accordingly, the model that accounts for projectile velocity and gun construction can be used to guide and improve barrel design.
Download or read book Prediction of Electromagnetic Fields Generated by Rail Guns written by and published by . This book was released on 1995 with total page 41 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electromagnetic launch systems such as rail guns generate electromagnetic signatures that contain a spectrum of frequencies extending from quasi-DC up to tens of kilohertz. However, electromagnetic compatibility (EMC) considerations pertaining to the potential adverse effects of these fields on nearby electronic equipment remain largely unexplored. This report includes a discussion of the theoretical models used to predict the inductance gradient, the transient behavior of the currents produced in the rail gun structure, the dynamical generation of the external fields, and a comparison of the theoretical model with experimental data. The predicted rail inductance gradient of L'sub R = 0.52 muH/m compares very well with the measured value of 0.522 muH/m. The existence of an inductance gradient efficiency factor, E sub 0, is demonstrated, with a derived value of 0.75. This produces an effective inductance gradient of L' = E sub 0 L' sub R = 0.39 muH/m. Using this value of L' leads to a theoretical exit muzzle velocity of 525 m/s, which is within 5 percent of the measured value.
Download or read book Projectile Oscillations in Augmented Rail Guns written by and published by . This book was released on 1986 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The projectile in an inductive store-powered rail gun, augmented by an external magnetic field, will oscillate under certain conditions. This behavior is easily understood when there is no resistance in the circuit comprising the storage coil, rails and armature. In this case, the flux in the complete circuit is conserved. However, as the projectile moves down the rails, more flux from the augmenting field is picked up. This must be accompanied by a decrease in current in the system to conserve the total flux. At a certain distance down the rails, the current must reverse to conserve the flux, and thus the force on the projectile reverses. This mechanism leads to oscillation of the projectile. An analytic solution is given for the case in which the resistance is zero.
Download or read book Science Abstracts written by and published by . This book was released on 1993 with total page 948 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fusion Energy Update written by and published by . This book was released on 1986 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Plasma Dynamics of the Arc Driven Rail Gun written by John D. Powell and published by . This book was released on 1980 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt: A model is analyzed to study the electromagnetic acceleration of particles using a rail gun. Current is conducted between the rails by a plasma arc which accelerates down the rails driving the projectile. The analysis includes determining the electromagnetic fields within the gun and solving the fluid-mechanical equations of the plasma under the assumption that the flow parameters are steady in a frame that accelerates with the arc. Specifically, a set of coupled equations is derived which, when solved, yields the properties of the arc and the acceleration of the projectile. A limiting-case analytic solution to the equations is found, and an iterative technique is employed to solve the equations numerically in the more general case. The results of the calculation are applied to analyze the arc in an experiment recently carried out by Rashleigh and Marshall. In addition, the properties of the arc appropriate for a larger rail gun, such as proposed in a forthcoming experiment by Westinghouse, are investigated and some approximate scaling relations derived. The results of the calculations are compared with those of others and some suggestions for future investigations are given.
Download or read book Rail Damage in a Solid Armature Rail Gun written by and published by . This book was released on 1987 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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 itself. The solid armature gun replaces the plasma armature with a conducting metal armature. Since the plasma arcing is reduced or eliminated, the projectiles are accelerated mainly by the Lorentz force. Thus, solid armature rail guns operate at lower projectile velocities. The important tradeoff is that there is a substantial reduction in rail damage for metal armature projectiles. The elimination of the plasma force limits projectile velocities in the metal armature rail guns. A more subtle limit is the speed at which the commutation process can take place. Although the latter limit is still not well understood, experimental evidence indicates a commutation limit may occur near 6 to 7 km/ sec. This velocity limit is still attractive for Army tactical missions for rail guns. The actual rail damage occurring with two types of metal armatures, wire brush contactors and monolithic metal contactors, and new developments in barrel technology, such as superconducting augmentation, are presented in this report.
Download or read book Barrel Wear Reduction in Rail Guns written by Michael Willet Smith and published by . This book was released on 2002 with total page 47 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis tests the effects a commercial silver paste has on the damage at the projectile-rail interface of a 4" long rail gun test section. Projectiles (0.635 x 0.635 x 0.953 cm) were pushed through the rail test section at 34 ł 19 m/s, while average current densities of 18-32 kA/cm2 was passed through the projectile - rail interface material. The specific objective is to examine rail and projectile damage at current densities near or above those (" 25kA/cm2) anticipated for a naval rail gun. Voltages across the rails were monitored and changes in conductivity when solid electrical contact was broken were observed. Silver deposits were observed on the rails from the paste at a peak current of 13.3 kA, while no damage was seen on the rails until a peak current of 17.2 kA was reached, which corresponds to average current densities of 22 kA/cm2 and 28.5 kA/cm2, respectively.
Download or read book SDI technology survivability and software written by and published by DIANE Publishing. This book was released on with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Armed Forces Journal International written by and published by . This book was released on 1988-08 with total page 1320 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Barrel Wear Reduction in Rail Guns An Investigation of Silver Paste Liquid Metal Interface written by and published by . This book was released on 2002 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis tests the effects a commercial silver paste has on the damage at the projectile-rail interface of a 4" long rail gun test section. Projectiles (0.635 x 0.635 x 0.953 cm) were pushed through the rail test section at 34 plus or minus 19 m/s, while average current densities of 18 - 32 kA/cm2 was passed through the projectile - rail interface material. The specific objective is to examine rail and projectile damage at current densities near or above those ( 25kA/cm2) anticipated for a naval rail gun. Voltages across the rails were monitored and changes in conductivity when solid electrical contact was broken were observed.
Download or read book Electrical Electronics Abstracts written by and published by . This book was released on 1997 with total page 1860 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Barrel Wear Reduction in Rail Guns written by Michael Willet Smith and published by . This book was released on 2002 with total page 47 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis tests the effects a commercial silver paste has on the damage at the projectile-rail interface of a 4" long rail gun test section. Projectiles (0.635 x 0.635 x 0.953 cm) were pushed through the rail test section at 34 ł 19 m/s, while average current densities of 18-32 kA/cm2 was passed through the projectile - rail interface material. The specific objective is to examine rail and projectile damage at current densities near or above those (" 25kA/cm2) anticipated for a naval rail gun. Voltages across the rails were monitored and changes in conductivity when solid electrical contact was broken were observed. Silver deposits were observed on the rails from the paste at a peak current of 13.3 kA, while no damage was seen on the rails until a peak current of 17.2 kA was reached, which corresponds to average current densities of 22 kA/cm2 and 28.5 kA/cm2, respectively.
