A SLOW-BURNING SOLID PROPELLANT WAFER ADD-ON

UTILIZING AN EXISTING NUMERICAL MODEL OF SWIRLING AND RECIRCULATING BASE FLOW, SIMULATIONS OF PROJECTILE BASE DRAG REDUCTION DUE TO BASE BLEED FLOW SHALL BE CARRIED OUT. MODIFICATIONS TO THE EXISTING CODE SHALL INCLUDE THE EXPLICIT DEPENDENCE OFTURBULENCE ON SWIRL AND NONAXISYMMETRIC EFFECTS IN THE AZIMUTHALLY-AVERAGED GOVERNING EQUATIONS. WITH THIS, THE EFFECT OF A HOT GAS INJECTION AT RELATIVELY LOW FLOW RATES, DUE TO A SLOW-BOURNING SOLID PROPELLANT WAFER AFFIXED TO THE PROJECTILE BASE, SHALL BE ASSESSED. A TYPICAL CONFIGURATION, MACH NUMBER AND REYNOLDS NUMBER SHALL BE SELECTED FOR PHASE I STUDIES WITH VARIOUS FLOW RATES INJECTION TEMPERATURES, AND PROJECTILE SPIN RATES. DURING THIS FEASIBILITY STUDY, THE SIZE AND WEIGHT PERTURBATIONS DUE TO THE WAFER SHALL BE IGNORED. HOWEVER, DURING PHASE I, THE PHASE II WORK PLAN SHALL BE WRITTEN AND INCLUDE A SYSTEM ANALYSIS WHICH OPTIMIZE THE WAFER SIZE/WEIGHT AND DRAG REDUCTION/TIME-OF-ACTION TRADEOFFS. ALSO, DURING PHASE II, THREE-DIMENSIONAL PHENOMENA INDUCED BY THE MAGNUE EFFECT SHALL BE ADDRESSED. FINALLY, GIVEN THE FEASIBILITY WHICH PHASE I SEEKS TO DEMONSTRATE RELATIVE TO LOW FLOW RATES (SMALL, SLOW-BURNING WAFERS) AND HIGH INJECTION TEMPERATURES, AN EXHAUSTIVE SET OF PHASE II COMPUTATIONS SHALL BE PLANNED AND COVER THE ENTIRE RANGE OF MACH AND REYNOLDS NUMBERS OF INTEREST.