Showing papers on "Projectile published in 1975"

Momentum distributions of isotopes produced by fragmentation of relativistic C-12 and O-16 projectiles

Abstract: The fragment momentum distributions in the projectile rest frame are, typically, Gaussian shaped, narrow, consistent with isotropy, depend on fragment and projectile, and have no significant correlation with target mass or beam energy. The nuclear temperature is inferred from the momentum distributions of the fragments and is approximately equal to the projectile nuclear binding energy, indicative of small energy transfer between target and fragment.

Relativistic Hydrodynamic Theory of Heavy Ion Collisions

Abstract: By use of finite-difference methods the classical relativistic equations of motion for the head-on collision of two heavy nuclei are solved. For $sup 16$O projectiles incident onto various targets at laboratory bombarding energies per nucleon less than or equal to2.1 GeV, curved shock waves develop. The target and projectile are deformed and compressed into crescents of revolution. This is followed by rarefaction waves and an overall expansion of the matter into a moderately wide distribution of angles.

On the Ballistic Impact of Textile Body Armor

Abstract: A mathematical model is developed and methods of analysis are formulated for determining the structural response of textile fabric flat panels subjected to ballistic impact by a dense projectile. A stepwise procedure in time is formulated which is suitable for either desk calculator use or for a digital computer in calculating strains, projectile position, forces, and decelerations as functions of time. Analytical results are compared with experimental data for impact of a .22 caliber fragment simulator impacting 1 ply and 12 ply nylon cloth as well as Kevlar (PRD)-49-IV cloth from 1–24 plies.

Optical Measurements of Muzzle Blast

Abstract: The structure of the flowfields formed about the muzzle of a small caliber rifle during the firing are measured using a time-resolved, spark shadow-graph technique. The initial flow from the muzzle occurs as tube gases are forced out ahead of the projectile. The gas is air and the exit properties are Ve =945 m/sec, Me = 1.48 and Pel POO = 15. A second flowfield forms upon separation of the projectile which releases the propellant gases. After an initial, in-bore expansion, the propellant gas muzzle properties are Ve=\29S m/sec, Afe = 1.0, and Pe/Poo =600. While the exit properties are different, the flowfields develop in a similar manner. In the axial or downrange direction, strong coupling between the jet and blast fields is observed; however, along the lateral boundaries, the coupling is very weak with the jet structure remaining invariant once established. Motion of observable discontinuities along the axis of symmetry is shown to qualitatively agree with variable energy blast wave theory. At late times, the air blast and jet flows are shown to uncouple and decay independently.

Impact fracture of composite sandwich structures

Abstract: An experimental investigation of impact-initiated failures in high-strength graphite/epoxy and Kevlar-49/epoxy sandwich structures has been conducted The tests consisted of firing small diameter aluminum projectiles with a velocity range of 16-67 meters/second (52-220 ft/sec) at preloaded sandwich specimens These tests were intended to be representative of service conditions on materials and structures which might be used as secondary aircraft components The preload and impact energy necessary to initiate catastrophic failure were determined The residual strength of impact-damaged specimens was also measured The results of these tests indicate that catastrophic failures in sandwich structures can be initiated at relatively low preloads by impact projectiles at energy levels well below that required to initiate visible damage

Apparatus for safely neutralizing explosive devices

Abstract: An unknown explosive device is safely neutralized, that is, rendered inoptive, without disturbing the device, by penetrating the device with an explosive-driven captive projectile from a safe distance and injecting liquid nitrogen into the device through the projectile to cool some internal parts below the temperature at which they are operative.

Armor piercing projectile

Abstract: An armor piercing projectile configuration which provides strength, rigidity and mass properties sufficient to permit long thin armor piercing cores to be fired from guns in a stable and accurate manner. The core is supported at both ends in such a way that a monocoque skin or shell provides rigidity and the space between the core and the shell is filled with rigid material or structure so as to support the core throughout substantially all of its length. The shell is of relatively high density adding to the lateral/transverse moment of inertia ratio to provide gyroscopic stability for the long thin core.

Missile fire-control system and method

Abstract: A surface-to-surface missile fire control system employing a pilot projectile fired into a predetermined indirect ballistic trajectory monitored by a fire-control station to determine its actual trajectory and actual coordinates of impact and wherein the pilot projectile has a camera for transmitting a target area picture to the fire-control station during its relatively steep descent. A pilot projectile laser directs a laser beam onto the target area surface to show the prospective impact point of the pilot projectile in a target area picture displayed at the fire-control station and a geographic position marking selector is manually operated to pick from the target area display and automatically enter into a fire-control computer the relative geographic coordinates of the projectile impact point and a selected target shown in the display, and the fire-control computer automatically calculates the coordinates of each selected target and aims a live projectile to the selected target in accordance with its calculated coordinates and the actual trajectory of the pilot projectile.

Aeroballistics of a Terminally Corrected Spinning Projectile (TCSP)

Abstract: This paper discusses the aerodynamic aspects and ballistic advantages of a method for providing terminal guidance to the Mk 41 projectile. Guidance and control functions are contained in a single unit, which is adaptable to the Mk 41 fuze-well. This unit contains all the required power system, sensors, and aerodynamic controls. These controls consist of a set of four canards in a cruciform arrangement. An overview is presented of the system concept. Indications are given of the increased effectiveness of the guided projectile over the conventional unguided round.

On the distribution of recoil momenta in a collision cascade

Abstract: For a collision cascade, initiated by a high-energy projectile, we calculate the average number of recoil particles which receive a specified kinetic energy and a specified direction of motion, relative to the initial direction of motion of the projectile. Characteristic for this expression is the fact that a δ-function, connecting these two parameters occurs in it.

Tennis practice machine

Abstract: Apparatus for collecting a projectile such as a tennis ball and launching it through the air is disclosed. The apparatus includes a conduit having an upstream end adapted to receive the projectile and a downstream end at which the projectile is expelled. A transfer valve is interposed in the conduit and prevents passage of air through the transfer valve towards the upstream end of the conduit. Suction is provided to the conduit immediately upstream of the transfer valve and forced air is provided immediately downstream of the transfer valve. The projectile is sucked through the conduit from the upstream end thereof to the transfer valve. The transfer valve allows the projectile to pass, and the forced air forces the projectile through the remainder of the conduit so that it is expelled at the downstream end thereof. A ball restraining flange may be interposed in the conduit downstream of the transfer valve to restrain the projectile until the forced air builds up to a predetermined pressure so that the projectile is expelled at relatively high velocity.

Dual purpose projectile and weapon combination

Abstract: Disclosed is a dual purpose projectile and weapon combination whereby an individual can select one of two different projectile configurations and consequent performance characteristics when firing a single projectile from the weapon. In one projectile configuration, the projectile has a conventional bullet-shaped body and a frontal area corresponding to its caliber. In the other projectile configuration, the projectile is configured to provide a low velocity short-range large frontal area missile having minimal penetration with high impact to obtain a disabling effect. The weapon has a barrel ring attachment which is rotatable to select the desired projectile configuration. The attachment includes a cutter selectively extensible into and retractable from the path of movement of the projectile through the barrel. The attachment also vents the weapon barrel to relieve pressure in the cutter area and this functions as a muzzle brake thereby reducing the velocity of the projectile when fired in its second configuration.

Laminated armor-piercing projectile

Abstract: A shatter resistant armor-piercing military projectile is disclosed. The struction comprises a plurality of high strength metallic lamellae interconnected with a high ductility alloy selected to provide an impact energy management system capable of maintaining the projectile's structural integrity during adverse operating conditions, such as oblique impact on spaced or solid armor targets.

Gun fired projectile having reduced drag

Abstract: A fumer exhibiting reduced base drag and a high specific impulse is provided by using as the pyrotechnic charge in the projectile a composition comprising a metal powder/alkaline earth metal compound formulation containing at least about 20 percent by weight of a plasticized resin and at least about 10 percent by weight of an active oxidizer for said resin. The metal powder is present in greater than stoichiometric amounts relative to the amount of alkaline earth metal compound and the pyrotechnic composition is effective to provide rapid burning in the near wake area of the projectile and fuel-rich combustion products.

Target, projectile and centrifugal projector

Abstract: A game of skill playable upon any terrain and incorporating a shaft for slinging a releasably engaged projectile toward a randomly positioned goal is disclosed. The shaft has a lateral spur extending outwardly. The projectile has a plurality of surfaces, at least two of which have a hole therein for engagement by the spur.

Gun muzzle flash suppressor

Abstract: This invention relates to new and improved methods and apparatus for suppsion of the light emissions of weapon systems capable of sustained gunfire, such as machine guns, and involves utilization of the projectile propellent gases to aspirate ambient air into the barrel of the weapon for ad-mixture with the gases, whereby the intensity of the light emissions during sustained firing of the weapon are substantially reduced In accordance with the present invention, a plurality of restricted orifices are provided in the gun barrel adjacent the muzzle thereof through which ambient air is aspirated

Incendiary payload for a heavy-duty ballistic projectile

Abstract: A ballistic missile is provided with an incendiary-type payload in which the incendiary composition is distributed around the ignition channel of the projectile within a plurality of successively disposed annular containers formed from a light metal alloy. Upon detonation, the individual containers forming the payload are successively ejected from the tail of the projectile in a ring-like pattern, and remain intact upon impact with the targeted terrain whereby the desired incendiary effect continues for a prolonged predetermined time.

Energy-absorbing sabot

Abstract: A one-piece sabot of the can type comprises an energy storage means posited between the obturator and the aft end of the subcaliber projectile and means for mounting the sabot on the projectile in one of a plurality of axial positions. Energy stored in the storage means during the initial phase of launch is released after launch to effect projectile-sabot separation.

Adjustable electrical time delay fuze

Abstract: An electrical time delay fuze for exploding a projectile in air over a tat comprises (1) a battery and voltage divider carried by the gun, (2) a firing circuit carried by the projectile including two capacitors initially connected in parallel with each other to be charged by the battery, prior to firing the gun, to two different voltages, switching means for subsequently connecting the capacitors in series with each other and with a timing resistor, and means for connecting the two capacitors to the cathode, anode and gate of a programmable unijunction transister (PUT) so that, after setback and projectile launch at firing, the two capacitors discharge through the resistor until the anode is sufficiently positive to the gate to cause the transistor to discharge through an electrical detonator and explode the projectile.

Impact response of graphite-epoxy flat laminates using projectiles that simulate aircraft engine encounters

Abstract: An investigation of the response of a graphite-epoxy material to foreign object impact was made by impacting spherical projectiles of gelatin, ice, and steel normally on flat panels. The observed damage was classified as transverse (stress wave delamination and cracking), penetrative, or structural (gross failure): the minimum, or threshold, velocity to cause each class of damage was established as a function of projectile characteristics. Steel projectiles had the lowest transverse damage threshold, followed by gelatin and ice. Making use of the threshold velocities and assuming that the normal component of velocity produces the damage in nonnormal impacts, a set of impact angles and velocities was established for each projectile material which would result in damage to composite fan blades. Analysis of the operating parameters of a typical turbine fan blade shows that small steel projectiles are most likely to cause delamination and penetration damage to unprotected graphite-epoxy composite fan blades.

Self-destruct fuze for spinning artillery projectile

Abstract: A fuze device to self-destruct a spinning projectile when the primary fuz system, such as mechanical time fuze or point detonating fuze, fails to function. The fuze utilizes separate locking devices which are each responsive to acceleration environments that a projectile experiences in a normal launch and flight. A setback pin, double resiliently mounted detents, spin detent, armed indicator, shutter, rotor, plunger, plunger lock and sac assembly containing silicone grease pressed on by blades of the rotor combine in a mechanically complementary design which insures that this self-destruct fuze may not be assembled armed in a projectile but will fire a projectile in which it is assembled in response to terminal deceleration of the projectile.

Non-explosive shaped-charge follow-through projectile

Abstract: A penetrating member for a projectile comprising a cylindrical mass body e from a high-density material and formed with a hardened front end in the form of a concavely curved scoop with an outstanding spike in its center. One end of a tubular liner abuts the scoop, the liner being made of an easily deformable, material. When the liner hits a target, the liner is forced back along the curve of the scoop and out the center of its tubular form as a high-velocity, target-penetrating jet of material.

Recoil Implantation of 18O from SiO2 by Heavy Projectiles

Abstract: The recoil implanation yield of oxygen atoms recoiled from thin, 18O enriched SiO2 layers into silicon substrates has been studied using the 180(p,α)15N nuclear reaction. For 24 keV Kr projectiles the 180 yield peaked at a thickness (~150 A) which approached the expected range of the Kr in SiO2, and ~2.5 oxygen atoms recoiled into the Si for each projectile. The cross section for recoiling into the Si was ~5 × 10-17 cm2/oxygen atom in the near-linear region stated above. For a fixed SiO2 thickness, the yield increased slightly with decreasing projectile energy until the projectile range was no longer greater than the oxide thickness.

Directional antenna for a projectile or rocket detonator

Abstract: In a projectile or rocket having a metal outer shell and including a proximity or influence detonator which operates with electromagnetic waves, particularly according to the reflected beam principle, and a directional antenna with a rotationally symmetrical radiation diagram for said detonator, the antenna is constituted by a circular slot which is coaxial with the longitudinal axis of the projectile or rocket and the antenna is excited with a line or cavity resonator disposed in the projectile or rocket and connected between the detonator and the antenna.

Avoidance of Guided Projectiles

Abstract: The game of two cars defined by Rufus Isaacs is visualized here in terms of missile avoidance by aircraft and torpedo avoidance by surface ships. Having the system dynamics specified and confined to the horizontal plane, the distinctiveness between the “problems” lies not only in the choice of parameters contained in Isaacs’ original model, but in the choice of target configuration and certain assigned player rationale as well. The guided projectile may or may not be using optimal guidance.

Enhancement of forward-angle cross sections in heavy-ion reactions because of projectile excitation

Abstract: Norman K. Glendenning and Georg Wolschin Lawrence Berkeley Laboratory University of California Berkeley, California 94720

Apparatus for stabilizing a liquid filled artillery projectile

Abstract: A highly permeable medium, such as an industrial foam, is utilized within e liquid payload cavity of a spinning artillery projectile to prevent flight instabilities produced by resonant oscillations of the liquid payload prior to the time it attains the spin velocity of the projectile. The highly permeable medium is preferably positioned near an end wall of the substantially cylindrical shell casing and physically acts to create highly viscous forces for causing the liquid in contact therewith to spin up to the projectile's velocity with a speed heretofore unrealized.