EVALUATION OF AN ADD-ON MUZZLE EXHAUST FLOW MANIPULATOR FOR NOISE SUPPRESSION ON LARGE CALIBER GUNS

UTILIZING NUMERICAL SIMULALTION TOOLS DEVELOPED BY THE PRINCIPAL INVESTIGATOR AND THE HOKENSON COMPANY FOR ARDEC, THE EVALUATION OF A SIMPLE AND LIGHTWEIGHT ADD-ON DEVICE TO MANIPULATE THE MUZZLE EXHAUST FLOW OF LARGE CALIBER GUNS IS PROPOSED. THE OBJECTIVE OF THESE SIMULATION IS TO DETERMINE THE SPECIFIC OPTIMUM GEOMETRIC CONFIGURATIONS OF THE GENERIC CONCEPT, ITS EFFECTIVENESS IN REDUCING THE RADIATED SOUND PRESSURE LEVEL AND THE REQUIREMENTS FOR PHASE II EXPERIMENTAL VALIDATION. BASED ON PREVIOUS AND ON-GOING STUDIES OF GUN FLOW FOR ARDEC, IT WAS NOTICED THAT THE INITAL RADIAL IMPULSE APPLIED TO THE AMBIENT FLOW BY THE GAS IMMEDIATELY BEHIND THE PROJECTILE CONTRIBUTES SIGNIFICANTLY TO THE TRANSIENT PRESSURE FIELD IN THE ENVIRONMENT. THEREFORE, THE CONCEPT TO CAPTURE THIS TRANSIENT RADIAL 'JET' AT THE MUZZLE, RE-DIRECT AND DIFFUSE IT WAS DEVELOPED. BY VARYING EACH OF THE LENGTHS WHICH CHARACTERIZE THE DEVICE, ITS PERFORMANCE RELATIVE TO NOISE SUPPRESSION MAY BE QUANTIFIED. SUBSEQUENTLY, MODIFICATIONS TO THE CONCEPT MAY BE INDICATED AND GUIDANCE FOR THE PHASE II EXPERIMENTAL VALIDATION STUDIES SHALL RESULT. ALL COMPUTATIONS SHALL BE PRESENTED ON COLOR VIDEOTAPE FOR EFFECTIVE COMMUNICATION OF THE TRANSIENT MULTI-DIMENSIONAL FLOW SOLUTIONS.