Very Low Drag Aerospike Projectile

Abstract

A projectile is provided for firing from a launcher, including an ogive nose; a cylindrical midsection joined to the nose; and a base curvature shaped as a modified aerospike nozzle. The aerospike base is created using a modified method of characteristics nozzle design process. The aerospike base allows for the efficient expansion of air behind the projectile to recover base pressure and reduce the overall drag of the projectile.

What is claimed is: 
     
         1 . A projectile for firing from a launcher, said projectile comprising:
 a fore nose;   a cylindrical midsection joined to said nose; and   a base curvature shaped as a modified aerospike nozzle.   
     
     
         2 . The projectile according to  claim 1 , wherein said nose is an ogive. 
     
     
         3 . The projectile according to  claim 1 , wherein the projectile contains explosives and fuse. 
     
     
         4 . The projectile according to  claim 1 , wherein the projectile is spin stabilized by launch from a rifled launcher. 
     
     
         5 . The projectile according to  claim 1 , wherein the projectile material is selected from the group consisting of copper or copper alloy-jacketed lead, tungsten, tantalum, alloys thereof and composites thereof. 
     
     
         6 . The projectile according to  claim 1 , wherein said nose is a hollow point. 
     
     
         7 . The projectile according to  claim 1 , wherein the projectile is launched in a sabot configuration. 
     
     
         8 . The projectile according to  claim 1 , wherein the flat end of said base is filled with energetic material to illuminate the trajectory of the projectile (tracer). 
     
     
         9 . The projectile according to  claim 1 , wherein the projectile is mounted into a bullet case. 
     
     
         10 . The projectile according to  claim 1 , wherein the base curvature is approximated as an aerospike by a polynomial, exponential, inverse power series, or trigonometric mathematical models. 
     
     
         11 . The projectile according to  claim 1 , wherein the base curvature is corrected from the modified short bell nozzle curvature by application of boundary layer theory to offset the curvature by the thickness of the viscous boundary layer created by the interaction of the air with the curvature.