DEVELOPMENT OF MATERIALS SUITABLE FOR TORPEDO NOSE WINDOWS

THE TORPEDO NOSE WINDOW APPLICATION REQUIRES MATERIALS WITH A UNIQUE COMBINATION OF PROPERTIES. THESE MATERIALS SHOULD BE STRONG, NOT VERY LOSSY, RELATIVELY INERT, ACOUSTICALLY WELL MATCHED TO SEAWATER, INEXPENSIVE, AND EASY TO FABRICATE. SOFT, RELATIVELY LOSSY RUBBERS HAVE BEEN USED SO FAR. TWO TECHNOLOGICAL DEVELOPMENTS OF RECENT YEARS FORESHADOW THE DEVELOPMENT OF IMPROVED MATERIALS WITH VERY LOW RISK. CASTABLE SYNTACTIC FOAMS HAVE BEEN PRODUCED WHICH COME CLOSE TO MATCHING BOTH THE DENSITY AND SOUND SPEED OF WATER. THE BEST CANDIDATES ARE BASED ON FLUORINATED PRECURSER MATERIALS. CERAMIC AND CARBON MICROSPHERES HAVE RECENTLY BECOME AVAILABLE THAT ARE MORE RUGGED THAN THEIR GLASS COUNTERPARTS. THIS PROJECT WILL EVALUATE THESE TWO TECHNOLOGIES. SYNTACTIC FOAMS MADE FROM BOTH ENGINEERING PLASTICS SUITABLE FOR EXTRUSION AND MOLDING, AND CASTABLE POLYMERS WILL BE PRODUCED WITH SPECIFIED ACOUSTIC PROPERTIES AND EVALUATED. THE MILLING/MIXING REQUIRED TO PROCESS THE FORMER MATERIALS DICTATES USE OF THE LESS FRAGILE FILLERS NOW AVAILABLE.