LOW REACTION FORCE NOZZLE USING UNSTEADY FLOW

THE REACTION FORCES REQUIRED TO OVERCOME THE THRUST OF A HANDLINE NOZZLE CREATES TIRING AND UNSAFE CONDITIONS FOR FIRE FIGHTERS, RESTRICTS THEIR ABILITY TO CONTROL THE NOZZLEAND ALSO LIMITS THE PRESSURES AND FLOW RATES WHICH CAN BE USED TO CONTROL A FIRE. IT IS DEMONSTRATED, BASED ON NEWTON'S LAWS OF MOTION, THAT A REDUCTION IN THE NET REACTION FORCE WITHOUT SUBSTANTIALLY REDUCING THE MASS FLOW AND DISCHARGE VELOCITY IS ONLY POSSIBLE USING AN UNSTEADY FLOW CONCEPT. USING THE UNSTEADY FLOW CONCEPTS DISCUSSED HERE, IT IS POSSIBLE TO REDUCE THE NET REACTION FORCE AT THENOZZLE TO A NEGLIGIBLE LEVEL WHILE INCREASING THE FIRE FIGHTING CAPABILITIES, E.G., INCREASING THE MASS FLOW AND DISCHARGE VELOCITY. THE PROPOSED EFFORT INCLUDES TESTING A PROTOTYPE NOZZLE TO VERIFY THE FEASIBILITY OF THE UNSTEADY FLOW APPROACH.