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 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 American Society for Composites American Society for Testing And Materials Committee D30 written by Erian Armanios and published by DEStech Publications, Inc. This book was released on 2004-10 with total page 1464 pages. Available in PDF, EPUB and Kindle. Book excerpt: Highlights the recent developments in the fundamental understanding of composites; important information for researchers and composite scientists.
Download or read book Acceleration of an Initially Moving Projectile written by Miguel Del GÃ1⁄4ercio and published by . This book was released on 2009-07-31 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the early 1980s, the principal mission for railguns required launch velocities in excess of 3 km/s. The focus of the research was centered on railguns employing plasma armatures. Significant efforts were expended on understanding the fundamentals of plasma armatures and their interaction with the bore. The temperatures associated with plasma armatures in railguns typically exceed 2 eV and, as a result, cause significant degradation in the bore materials leading to degradation of railgun performance. One parameter that seemed to ameliorate the effect of long dwell time was the use of a projectile injected into the breech of the railgun. This technique was often used with inert gas as the propulsive media. However, propellants were evaluated (1) and used to inject propellant-accelerated projectiles into the breech of a railgun (2). The burning propellant gases were insufficiently conductive to break down and form a plasma arc with 6000 V applied across the breech of the railgun. While no deleterious interactions were noted between the combustion products and plasma electrodynamics, the research was plagued with large variability in the injection velocity, obturation in the squarebore railgun, and reliable initiation of the plasma. All challenges were eventually solved. More recently, the mission for railguns has found utility using velocities
Download or read book DESIGN AND OPTIMIZATION OF AN ELECTROMAGNETIC RAILGUN written by and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract : Railgun is a future weapon for shooting long-range targets with high accuracy. Railgun is an economical weapon as it does not use any kind of propellant for shooting a projectile. It uses high impulsive current to generate the necessary force required to hit the target. The US Navy has been planning to implement railgun system on ships as their long-range shooting weapon. Railgun needs to be charged up to a certain voltage level to generate the necessary force to shoot the projectile to achieve the specified target location. It is very important that minimal voltage is required for shooting the projectile to hit the target accurately as it minimizes the losses occurring in the railgun system. This project focuses on solving this challenge by minimizing the railgun's initial voltage required to shoot a projectile for hitting the target with high accuracy. It also focuses on minimizing the copper losses occurring in the system. In this project, a novel method has been generated which solves both challenges. In this project, a model of the discharging circuit of the railgun and a model of the projectile's trajectory with and without air drag have been generated using Simulink. Then both of these models are merged using MATLAB. Once this model was complete, it simulates the discharge of the capacitor voltage into the railgun system to achieve the necessary acceleration required to launch a projectile with a certain velocity. It also simulates the trajectory of a projectile. In this project, an optimization technique has been implemented using Fmincon to optimize the shooting accuracy to hit the target with minimum copper losses. This has been achieved by generating a code which optimally chooses the initial input voltage required for discharging and the launch angle at which the railgun is kept. At the end, higher than 97.5 % accuracy has been achieved in hitting the target while reducing the copper loss by more than 6 % for both the cases that were modeled.
Download or read book Armor written by and published by . This book was released on 2009 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Approximate Analysis of Balloting Motion of Railgun Projectiles written by and published by . This book was released on 1991 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the final of three reports dealing with the in-bore balloting motion of a projectile fired from an electromagnetic railgun. Knowledge of projectile in-bore motion is important to its design and the design of the railgun. It is a complicated problem since many parameters are involved and it is not easy to determine the interacting relationships between them. To make the problem easier to understand it was analyzed on several levels. Beginning from the basic simple model which computed only the axial motion, more complicated models were introduced in upper levels that included the more significant lateral forces and gun tube vibration effects. This report deals with the approximate analysis of balloting motion. This model considers the effects of the propulsion force, the friction force of the projectile package (projectile and armature), air resistance, gravity, the elastic forces, and the projectile/ barrel clearance. To simplify the modeling, a plane motion configuration is assumed. Though the projectile is moving with a varying yaw angle, the axes of the barrel and the projectile package, and the projectile center of gravity are always considered in a plane containing the centerlines of the rails. Equations of motion are derived and solved. A sample computation is performed and the results plotted to give a clearer understanding of projectile in-bore motion.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 836 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Basic Simple Modeling of In Bore Motion of Railgun Projectiles written by and published by . This book was released on 1991 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: In an electromagnetic railgun a projectile encounters a complex force environment during launch. A thorough understanding of these forces is critical to projectile and gun tube design. There are many parameters involved and interacting relationships which must be determined. To better understand and establish the in-bore force models, we begin with a basic simple model which computes only the axial motion. More complicated models will be introduced in subsequent reports which will include lateral forces and gun tube vibration effects. This report deals with a very simple axial motion model. Only the effects of the propulsion force, projectile package mass, air resistance, and the friction forces are presented. Equations of motion are derived and solved. A sample computation with available data is performed and curves plotted to give clearer understanding of the results.
Download or read book You Pay We Slay written by William Alan Webb and published by Hit World Press. This book was released on 2022-01-26 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Want somebody dead? If you do, the solution's easy. Hire LifeEnders, Inc. You pay. We slay.Whether you know it or not-whether you believe it or not-the world is a dangerous place full of criminals, terrorists, monsters, sorcerers, extra-terrestrials, inter-dimensional predators, and embarrassing relatives. And, for the right price, they can all go away.Twenty years ago, LifeEnders became the first legal corporation of assassins to operate on U.S. soil. Today, LEI has a hit man in every state and many foreign nations. Getting rid of the scammer who catfished Grandma only requires the requisite credit line, and porch thieves now think twice if a security camera might identify them. You pay; we slay. No questions asked.But it's not just about putting a target in the cross-hairs. Sometimes the job requires 'Special Skills,' and that costs extra. If a giant orange rhinoceros appears in the sky? Call LEI and let the Special Activities Division handle it?and don't forget your credit card.The first Hit World anthology brings together an all-star lineup of amazing authors guaranteed to keep you awake past bedtime.Sorry. (Not Sorry)
Download or read book Civilizations written by Wallace Horta and published by Talentos da Literatura Brasileira. This book was released on 2020-09-18 with total page 227 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first book in the Civilizations Trilogy broke new ground by introducing the protagonists of a civilization like never before. Prepare yourself for a completely new, completely original First Contact. Astronauts Susan and Michael approach an unidentified space object, which developed a close-to-the-Sun trajectory and then moved itself to the far side of our Moon. Upon making contact, Susan goes through a series of relevant events from another planet, crossing from one era to another in company of Michael, who was acting strangely, as if he was part of all of that. Centuries later, Susan no longer feels like a foreigner among that people. In company of Electrons and aboard the Eclipsed Star, she crosses the colossal Continuum Warpers, playing a role in shaping the fate of the galaxy. That is what has happened to Fount, and it is done that way because only in the clarity of whole truth exists the possibility of accepting each other within the limits of what each civilization truly can be.
Download or read book Hearing on National Defense Authorization Act for Fiscal Year 2009 and Oversight of Previously Authorized Programs Before the Committee on Armed Services House of Representatives One Hundred Tenth Congress Second Session written by United States. Congress. House. Committee on Armed Services. Subcommittee on Terrorism, Unconventional Threats, and Capabilities and published by . This book was released on 2009 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hypervelocity Gouging Impacts written by John D. Cinnamon and published by Progress in Astronautics and Aeronautics Series. This book was released on 2009 with total page 233 pages. Available in PDF, EPUB and Kindle. Book excerpt: When materials interact at hypervelocityon the order of Mach 8.5 and aboveunexpected results can occur. This book addresses the effects of hypervelocity impact, summarizing past and present research efforts as well as setting out the theoretical foundation for understanding material interactions at such velocity. It focuses on research conducted at the Holloman Air Force Base High Speed Test Track (HHSTT), which is working toward a test vehicle speed above Mach 10. Researchers have found that as the sleds speed has increased to Mach 8.5, a material interaction has developed which causes gouging in the rails and the sleds shoeswhich can lead to catastrophic failure.
Download or read book Energy Research Abstracts written by and published by . This book was released on 1989 with total page 632 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Official Gazette of the United States Patent and Trademark Office written by and published by . This book was released on 1990 with total page 636 pages. Available in PDF, EPUB and Kindle. Book excerpt:
