Predicting bore deformations and launcher stresses in railguns

Davidson, R.F.; Cook, William A.; Rabern, D.A.; Schnurr, N.M.

doi:10.1109/tmag.1986.1064668

Cited by 11 publications

(2 citation statements)

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“…In this study, both friction and wear of sliding electrical contacts were investigated using a specially designed tribo-simulator, described in detail in a previous work [13]. The normal loads and currents were selected to replicate the contact pressures and current densities typical of electromagnetic launchers [14,15], the study of which serves as the primary motivation for the current investigation. Aluminum (Al 6061) hemispherical pins, with radius of curvature of 6.35 mm, were slid against Al 6061 flats for a distance of 2 m (unidirectional sliding) for various combinations of speed, current, load, and surface roughness.…”

Section: Methodsmentioning

confidence: 99%

Effect of Operating Conditions on Tribological Response of Al–Al Sliding Electrical Interface

Bansal

Streator

2011

Tribol Lett

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Aluminum is widely used in electrical contacts due to its electrical properties and inexpensiveness when compared to copper. In this study, we investigate the influence of operating conditions like contact load (pressure), sliding speed, current, and surface roughness on the electrical and tribological behavior of the interface. The tests are conducted on a linear, pin-on-flat tribo-simulator specially designed to investigate electrical contacts under high contact pressures and high current densities. Control parameters include sliding speed, load, current, and surface roughness. The response of the interface is evaluated in the light of coefficient of friction, contact resistance, contact voltage, mass loss of pins, and interfacial temperature rise. As compared to sliding speed, load, and roughness, current is found to have the greatest influence on the various measured parameters. Under certain test conditions, the interface operates in a ''voltage saturation'' regime, wherein increase in current do not result in any increase in contact voltage. Within the voltage saturation regime the coefficient of friction tends to be lower, a result that is attributed to the higher temperatures associated with the higher voltage (and resulting material softening). Higher interfacial temperatures also appear to be responsible for the higher wear rates observed at higher current levels as well as lower coefficients of friction for smoother surfaces in the presence of current.

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Section: Methodsmentioning

confidence: 99%

Effect of Operating Conditions on Tribological Response of Al–Al Sliding Electrical Interface

Bansal

Streator

2011

Tribol Lett

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“…В [34][35][36] внимание было уделено проблеме механической устойчивости ка-нала ускорения рельсотрона, так как со-здание жёсткой рельсовой конструкции при уровне токов свыше 6 10 А является сложной инженерной задачей. Ещё одной сложной проблемой на пути достижения сверхвысоких скоростей стало явление развала плазменного поршня за счёт по-ступления продуктов эрозии электродов и самого материала плазмы якоря в засна-рядное пространство [37].…”

Section: рис 2 схема рельсового ускорителяunclassified

Methods and means of accelerating particles of natural and technogenic origin

Сёмкин

Сухачёв

Dorofeev³

2016

VESTNIK of Samara University. Aerospace and Mechanical Engineer

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Анализируются различные типы ускорителей твёрдых макрочастиц естественного и техногенного происхождения. Рассмотрены конструкции и принципы работы ускорителей микронного и миллиметро-вого диапазона с центром распределения по скоростям около 20 км/с: электростатические, электродина-мические, импульсные, pельсовые электромагнитные, катушечные электромагнитные и электроразряд-ные газодинамические, комбинированные установки. Проведён обзор легкогазовых, взрывных, газораз-рядных и электромагнитных ускорителей с различными принципами действия. Основное внимание уде-лено электромагнитным методам ускорения, которые наиболее перспективны для ускорения макротел до сверхвысоких скоростей. Указаны достоинства и недостатки различных типов ускорителей твёрдых тел. Проведён анализ пригодности различных конструкций ускорителей для имитации столкновений орби-тальных метеоритных частиц и элементов космического мусора с поверхностью космического аппарата. Определены проблемы, возникающие при построении и работе ускорителей различного типа, и приве-дены решения этих проблем. Приведены результаты экспериментов по ускорению твёрдых тел микрон-ного и миллиметрового диапазона на ускорителях различного типа и методы оптимизации конструкций ускорителей макрочастиц с целью увеличения их КПД и скорости ускоряемого тела. Приведена эволю-ция ускорителей и основные направления их дальнейшего совершенствования.Рельсотрон, катушечный ускоритель, резонансный ускоритель, электроразрядный ускоритель, метание частицы естественного и техногенного происхождения, высокоскоростное ускорение твёр-дых макрочастиц, ускорители, принцип работы, конструкция, эффективность.

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Rail electrodynamics in a plasma armature railgun

Rolader

Jamison

Villecco

et al. 1991

Journal of Applied Physics

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A model is developed to investigate rail electrodynamics in a plasma armature railgun. This model describes the rail motion in response to the transitory Lorentz force and the compressive restoration force from the material which is between the rails and the containment structure. In this model the distance between the rails is found to oscillate with a frequency of /3. The magnetic field and the dynamic behavior of the rails induce local electric fields. We investigate the significance of these electric fields in the laboratory frame and in the projectile frame. In the lab frame, rail electrodynamics induces local electric fields which have maximums spaced behind the projectile at locations where pt, is an odd multiple of ?r, where tp is the time since the projectile has passed an axial location on the rails. When the projectile is accelerating, rail dynamics induce electric fields in the projectile frame which have maximums where &, is an even multiple of n: As the projectile velocity increases, the locations of the peak voltages move farther behind the projectile. For the CHECMATE railgun, calculations indicate that the rail displacement is on the order of 2 mm, the rail velocity is on the order of 50 m/s, and the voltages induced in the projectile frame are on the order of 20-40 V.

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Predicting bore deformations and launcher stresses in railguns

Cited by 11 publications

References 1 publication

Effect of Operating Conditions on Tribological Response of Al–Al Sliding Electrical Interface

Effect of Operating Conditions on Tribological Response of Al–Al Sliding Electrical Interface

Methods and means of accelerating particles of natural and technogenic origin

Rail electrodynamics in a plasma armature railgun

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