A COLD FLOW TEST FACILITY FOR IR SUPPRESSORS

THE PRESENT NEED TO TEST IR SUPPERSSORS ON APPLICATION ENGINES INCURS SIGNIFICIANT COSTS DUE TO THE REQUIREMENTS OF A FULL-SCALE ENGINE INCLUDING: ITS FUEL UE, SAFE EXHAUST DISPOSAL, AND THE NECESSITY OF UTILIZING FULL-SCALE, HEAT-RATED SUPPRESSOR PROTOTYPES. THESE COSTS CAN BE REDUCED USING A CORRECTLY SCALED AMBIENT TEMPERATURE TEST FACILITY. RELIABLE ESTIMATES OF GAS TURBINE ENGINE EXHAUST SYSTEM PERFORMANCE CAN BE OBTAINED FROM COLD FLOW SIMULATIONS BY USING A STAGNATION TEMPERATURE SIMILARITY PRINCIPLE. THE USE OF SUCH SIMILARITY ALONG WITH POSSIBLE SCALING OF THE PHYSICAL SIZE OF THE FLOW ALLOWS A LABORATORY SIMULATION FACILITY TO BE REALIZED - A PROPOSED COLD FLOW TEST STAND (CFTS). THE DESIGN OF THIS FACILITY WILL BE OPTIMIZED FOR THE FLOW MEASUREMENTS MOST USEFUL FOR ASSESSING IR SUPPRESSOR PERFORMANCE, INCLUDING VELOCITY AND MIXING FLOW DIAGNOSITC TECHNIQUES. THE PROPOSED CFTS WILL BE DESIGNED TO SIMULATE THE EXHAUST FLOW OF THE CLASS OF TURBO-SHAFT ENGINES USED IN HELICOPTERS. A PHASE I WORK PLAN HAS BEEN DEVELOPED TO CCOMPLISH SEVERAL TECHNICAL OBJECTIVES NEEDED TO DEVELOP THE CFTS. THESE INCLUDE DEVELOPMENT OF SIMILARITY CONCEPTS FOR SCALING THE FLOW AND OF VALIDATION AND MEASUREMENT PROCEDURES AND DIAGNOSTICS TO PROVIDE A RELIABLE FOUNDATION FOR MAKIG USE OF THE ANTICIPATED TEST RESULTS.