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Model helicopter rotor high-speed impulsive noise: measured acoustics and blade pressures
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Boxwell, D. A. Schmitz, F. H. Schultz, K. J. Splettstoesser, W. R. |
| Copyright Year | 1983 |
| Description | A 1/17-scale research model of the AH-1 series helicopter main rotor was tested. Model-rotor acoustic and simultaneous blade pressure data were recorded at high speeds where full-scale helicopter high-speed impulsive noise levels are known to be dominant. Model-rotor measurements of the peak acoustic pressure levels, waveform shapes, and directively patterns are directly compared with full-scale investigations, using an equivalent in-flight technique. Model acoustic data are shown to scale remarkably well in shape and in amplitude with full-scale results. Model rotor-blade pressures are presented for rotor operating conditions both with and without shock-like discontinuities in the radiated acoustic waveform. Acoustically, both model and full-scale measurements support current evidence that above certain high subsonic advancing-tip Mach numbers, local shock waves that exist on the rotor blades ""delocalize'' and radiate to the acoustic far-field. |
| File Size | 3570607 |
| Page Count | 35 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19840001953 |
| Archival Resource Key | ark:/13960/t14n4160g |
| Language | English |
| Publisher Date | 1983-09-01 |
| Access Restriction | Open |
| Subject Keyword | Aerodynamics Propeller Blades Impulses Scale Models Pressure Measurement Blade Slap Noise Noise Measurement Rotary Wings Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
