Projectile

About: Projectile is a research topic. Over the lifetime, 13047 publications have been published within this topic receiving 115563 citations.

Precision guided extended range artillery projectile tactical base

Abstract: A tactical base for a guided projectile includes a base structure, and an adaptor structure for securing the base structure to a forward section of the projectile. The base further includes a plurality of fin slots, with a plurality of insert structures fitted into corresponding ones of the fin slots. A plurality of deployable fins are pivotally mounted to the base structure and supported within the insert structures for movement between a stowed position and a deployed position.

Numerical Computations of Transonic Critical Aerodynamic Behavior

Abstract: The determination of aerodynamic coefficients by shell designers is a critical step in the development of any new projectile design. Of particular interest is the determination of the aerodynamic coefficients at transonic speeds. It is in this speed regime that the critical aerodynamic behavior occurs and a rapid change in the aerodynamic coefficients is observed. Three-dimensional, transonic, flowfield computations over projectiles have been made using an implicit, approximately factored, partially flux-split algorithm. A composite grid scheme has been used to provide the increased grid resolution needed for accurate numerical simulation of three-dimensional transonic flows. Details of the asymmetrically located shock waves on the projectiles have been determined. Computed surface pressures have been compared with experimental data and are found to be in good agreement. The pitching moment coefficient, determined from the computed flowfields, shows the critical aerodynamic behavior observed in free flights. I. Introduction T HE flight of projectiles covers a wide range of speeds. The accurate prediction of projectile aerodynamics at these speeds is of significant importance in the early design stage of a projectile. The critical aerodynamic behavior occurs in the transonic speed regime, 0.9

Oblique detonation stabilized on a hypervelocity projectile

Abstract: We present new experimental results demonstrating the initiation and stabilization of an oblique detonation by a hypervelocity projectile Projectiles 25 mm in diameter were launched at nominal velocities of 2700 m/s into stoichiometric H 2 -O 2 -N 2 mixtures at pressures between 01 and 25 bar A critical threshold in initial pressure was found to be required for the establishment of detonations Initiation events similar to DDT in propagating waves were observed after 300 mm of travel in H 2 -O 2 mixtures diluted with 25% N 2 A more direct initiation process was observed in H 2 -air mixtures A stabilized but overdriven oblique detonation was observed in a stoichiometric H 2 -air mixture at an initial pressure of 25 bar The pressure threshold can be explained in terms of competing reaction and flow-quenching effects along a curving streamline in supersonic flow behind a curved shock wave This competition can be characterized by a critical Damkohler number Da 0 , which is inversely proportional to the product of wave curvature κ and reaction zone thickness Δ Only if the reaction zone is sufficiently thin in comparison with the projectile, Da>Da 0 , is it possible to obtain stabilized detonations Otherwise, the reactions quench and the wave splits into a nonreactive shock wave followed by flamelike contact surface The inverse pressure dependence Δ∼ P 0 −1 of the reaction zone length and the scaling of the wave curvature κ∼1/ a with the body radius a implies the standard binary scaling relationship P 0 a =constant for the critical conditions of stabilization for a given mixture composition characterized by a bimolecular rate-limiting step