| Popis: |
The paper is a general interest one dealing with the way in which acoustic techniques and knowledge assist in the instrumentation, testing and development of Aero Engines. No attempt is made to deal with “Sonic Analysis”, i.e. the technique whereby an external microphone allegedly enables the condition of each and every part of the engine to be determined, nor to deal with the general external noise produced by engines; both of which are subjects in themselves. The use of varied methods of extracting and processing information from compressor blading, turbines, gears, bearings, canware and carcass of the engine are dealt with in some detail as is the associated Sound Room work. The help which can be given by ear and brain in a number of these cases is dealt with as a valuable complement to instrumental analysis, especially in revealing effects easily missed by instruments alone. Coupled vibrations between engine parts and between engine and structure or power off-take are considered and the latest methods for their measurement discussed. The original paper was provided with tape recorded audio representations of many of the effects as heard by the ear; however, the present state of the art does not permit their reproduction here. |
