Development and Testing of a High Level Axial Array Duct Sound Source for the NASA Flow Impedance Test Facility
نویسندگان
چکیده
2 INTRODUCTION 3 I. THEORY 4 A. DUCT ACOUSTICS AND SOURCE-DUCT INTERACTION 4 1. SOURCE-DUCT INTERACTION 4 2. SOURCE INTERNAL IMPEDANCE 5 3. THROAT IMPEDANCE 5 4. DUCT IMPEDANCE 6 5. CALCULATING THE DOWNSTREAM PRESSURE DUE TO A PISTON 8 6. THEORETICAL RESULTS AND IMPLICATIONS 8 7. PASSIVE EFFECT OF SOURCES 10 8. EXPERIMENTALLY DETERMINING REFLECTION AND TRANSMISSION 10 B. CALCULATING OPTIMAL DRIVE SIGNALS 11 1. A FREQUENCY DOMAIN METHOD FOR CREATING HIGH LEVEL TONAL NOISE 12 2. A TIME DOMAIN METHOD FOR CREATING HIGH LEVEL PULSES 13 3. EFFORT WEIGHTING AND ERROR ANALYSIS 15 4. MAXIMIZING OUTPUT (LOOP OPTIMIZATION) 15 II. EXPERIMENTAL RESULTS 16 1. MEASUREMENTS OF DUCT SOURCE INTERACTION 16 2. MULTIPLE SOURCES 16 3. PASSIVE REFLECTION AND TRANSMISSION 17 4. SINGLE FREQUENCY EXCITATION 17 5. PULSE GENERATION: EFFORT WEIGHTING AND MAXIMIZING OUTPUT 18 6. PULSE GENERATION: EXPERIMENTAL RESULTS 19 III. CONCLUSIONS 20 ACKNOWLEDGEMENTS 22 REFERENCES 23
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تاریخ انتشار 2000