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Analysis of noise measured from a propeller in a wake
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Block, P. J. W. |
| Copyright Year | 1984 |
| Description | In this experimental study, the acoustic characteristics of a propeller operating in a wake were studied. The propeller performance and noise were measured from two 0.25 scale propellers operating in an open jet anechoic flow environment with and without a wake. One propeller had NACA 16 series sections; the other, ARA-D. Wake thicknesses of 1 and 3 propeller chords were generated by an airfoil which spanned the full diameter of the propeller. The airfoil wake profiles were measured. Noise measurements were made in and out of the flow. The propellers were operated at 40, 83, and 100 inf of thrust. The acoustic data are analyzed, and the effects on the overall sound pressure level (OASPL) and scaled A weighted sound level L sub A with propeller thrust, wake thickness, and observer location are presented. The analysis showed that, generally, the wake increased the overall noise (OASPL) produced by the propeller; increased the harmonic content of the noise, thus the scaled L sub a; and produced an azimuthal dependence. With few exceptions, both propellers generally produced the same trends in delta OASPL and delta L sub a with thrust and wake thickness. |
| File Size | 6666545 |
| Page Count | 49 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19850003480 |
| Archival Resource Key | ark:/13960/t1ng9gr8q |
| Language | English |
| Publisher Date | 1984-11-01 |
| Access Restriction | Open |
| Subject Keyword | Acoustics Thickness Propellers Wind Tunnel Tests Aircraft Wakes Aerodynamic Noise Airfoils Noise Measurement Thrust Sound Pressure Dynamic Pressure Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Technical Report |
