PERCUSSIVE JET CUTTING

THE PERCUSSIVE JET IS PROPOSED AS A MORE RAPID AND ENERGY EFFICIENT MEANS OF CUTTING REINFORCED CONCRETE AND STEEL THAN LASERS, ABRASIVE BLASTING, OR ABRASIVE JETTING. THE IMPACT CHARACTERISTICS OF PERCUSSIVE JETS (INITIAL IMPACTS, TENSILE FAILURE, AND PERSISTENCE) ALLOW TARGETS TO BE CUT IN WAYS NEVER BEFORE ATTEMPTED. FOR INSTANCE, AT 30,000-PSIG DISCHARGE PRESSURE, CALCULATIONS SHOW THE POSSIBILITY OF STRIKING TARGET MATERIAL WITH IMPULSES GREATER THAN THE ULTIMATE STRENGTH OF HIGH-STRENGTH STEEL, OVER 10,000 TIMES PER SECOND! PERCUSSIVE JETS APPLY FORCE TO ROCK AS A SEQUENCE OF HIGH-FREQUENCY, SHORT-DURATION IMPACTS, RATHER THAN STEADILY. THESE JETS CAN BE PRODUCED WITH A CONVENTIONAL, CONTINUOUS-FLOW SYSTEM BY MODULATING THE DISCHARGE, THAT IS, CYCLING THE DISCHARGE RATE BY A SMALL AMOUNT ABOVE AND BELOW ITS AVERAGE. WITH MODULATED DISCHARGE, THE FASTER PART OF EACH CYCLE OVERTAKES THE SLOWER IN THE FREE STREAM. IF THIS PROCESS ISDONE PROPERLY, THE STREAM BECOMES BUNCHED INSTEAD OF UNIFORMAND A PERCUSSIVE JET IS PRODUCED. PREVIOUS RESEARCH WITH PERCUSSIVE JETS HAS BEEN SUMMARIZED. AREAS IN WHICH THE TECHNICAL FEASIBILITY NEEDS TO BE DEMONSTRATED ARE IDENTIFIED AND USED FOR A SOURCE OF PHASE I WORK. IN THIS WAY, THE FEASIBILITY OF ALL ITEMS NECESSARY TO FORM A GOOD FOUNDATION FOR THE PHASE II EFFORT WILL BE PROVEN. DATA WILL BE OBTAINED TO INDICATE THE OPERATING CONDITIONS NECESSARY TO ACCOMPLISH PHASE II OBJECTIVES.