The interim prediction for aircraft noise
Abstract
The acoustic emission from an aircraft during the flight is a dynamic process. The emitting acoustic power and received mean square acoustic pressure are the function of time. The paper deals with this problem as a quasi-steady one. The whole process is resolved into several elementary procedures, for example, the flight trajectory, the geometric relation between the noise sources and observers, the noise source characteristics,the air propagation, and ground effect. Two calculation examples are given, one for a long-range passenger aircraft with high bypass-ratio turbofan engine, another for a three-bladed propeller. The composition of aircraft noise, and its time record, frequency spectrum and directivity can be clearly described by these curves.
- Publication:
-
Acta Aeronautica et Astronautica Sinica
- Pub Date:
- August 1990
- Bibcode:
- 1990AcAAS..11..334T
- Keywords:
-
- Acoustic Excitation;
- Engine Noise;
- Noise Prediction (Aircraft);
- Effective Perceived Noise Levels;
- Flight Paths;
- Ground Effect (Aerodynamics);
- Sound Pressure;
- Temporal Distribution;
- Acoustics