UFFA- Universal Fan Facility for Acoustics: An Enhancement of Europe's Largest Aero Acoustic Test Facility for Aero Engine Fans

摘要

The Universal Fan Facility for Acoustics (UFFA) and the associated anechoic chamber were specifically designed to satisfy the need for advanced testing and investigation of aero engine fan noise. Fans with diameters of up to 869 mm (34.2-inch) can currently be tested with up to 10,400 RPM powered by an 18 MW electric motor. This paper describes the concept and general design of UFFA. Information is given on test capabilities, performanceoise characteristics and first operational experience. Fan forward noise can be analyzed with the standard far field measurements in the anechoic chamber. In addition, fan forward and fan rearward noise can be analyzed by using circumferential mode analysis based on circumferential arrays of microphones. A radial mode analysis (necessary for the estimation of the acoustic power) is also possible using radial and/or axial arrays of microphones with variable circumferential position. A modern fan owned by AneCom with a nominal fan-pressure ratio of 1.5 is used in the present study to evaluate the influence of a turbulence control screen (TCS) (also called inlet control device, ICD) on the radiated noise. The fan performance map is reported in which the working points of the acoustic tests, running from nominal shaft speeds of 60 % to 105 % are indicated. It was found that the TCS reduces the noise radiation into the upstream direction by up to 12 dB, primarily affecting tones at multiples of the shaft frequency. The influence of the TCS is much smaller in the downstream direction.