BASE DRAG ADVERSELY IMPACTS PROJECTILE RANGE.

BASE DRAG ADVERSELY IMPACTS PROJECTILE RANGE. REDUCTION OF BASE DRAG CAN LEAD TO IMPROVED PROJECTILE RANGE. THERE ARE SEVERAL APPROACHES THAT CAN POTENTIALLY BE EMPLOYED TO DECREASE BASE DRAG SUCH AS BASE BLEED AND EXTERNAL BURNING. A COMBINATION OF THESE CONCEPTS WILL BE ANALIZED USING AN UNSTEADY NAVIER STOKES COMPUTER CODE. THESE TYPE OF CODES HAVE BEEN USED PREVIOUSLY TO ANALYZE THE FLOW FIELD IN BASE REGIONS WITH INJECTION. MOST OF THIS PREVIOUS WORK CONCERNING PROJECTILE DRAG REDUCTION EMPLOYED INJECTION OF AIR NEAR THE PROJECTILE BASE CENTERLINE. THE PROPOSED EFFORT WOULD 1) INVESTIGATE THE USE OF FOREIGN SPECIE INJECTION SUCH AS HELIUM, CARBON DIOXIDE OR SOLID PROPELLANT EXHAUST PRODUCTS AND 2) THE EFFECT OF ANGLED INJECTION NEAR THE PROJECTILE BASE OUTER DIAMETER. THE APPLICATION OF THIS TYPE OF COMPUTER CODE WOULD ALLOW FOR RAPID AND RELIABLE SCREENING AND OPTIMIZATION OF LOW BASE DRAG CONCEPTS. THE END RESULT WOULD BE DEVELOPMENT OF PROJECTILE CONFIGURATION GUIDELINES FOR OBTINING INREASED RANGE.