In November 2005 a Workshop with the title ”Active Control of Aircaft Noise – Concept to Reality” was organised by CEAS-ASC (Council of European Aeronautical Societies – Aeroacoustics Specialist Committee). The Workshop was held at KTH (the Royal Institute of Technology) in Stockholm, Sweden and was chaired by Hans Bodén from KTH and Urban Enborg from A2 Acoustics. This was the ninth in a series of annual Workshops organised by CEAS-ASC. It was co-sponsored by_the American Insitute of Aeronautics and Astronautics (AIAA), CARAN SAAB Engineering, SAAB, Airbus, KTH and the EU through the X2-Noise Thematic Network.
A total of 20 papers were presented during the two day event divided into four sessions: interior noise, airframe noise flow control, jet noise and fan noise.
The aim of the Workshop was to summarise the state of the art and to indentyfy breakthroughs needed in order to apply active control in reducing aircraft noise. The technique is most mature in control of interior noise where there are 850 systems flying in regional turnoprop aircraft , business turboprop and some jet aircraft and military aircraft. There has been a lot of work on active control of fan noise both on active liners and using flow control to reduce fan tone noise and active control of buzz saw noise. Also for airframe noise there have been studies e.g., on applying active flow control to highlift devices. Closed-loop flow control has been used in control of cavity tones. Studies have also been made of the use of flow injection for reduction of jet noise. Another technique tested for jet noise reduction is deployable chevrons.
The present issue contains five of the twenty papers presented at he Workshop. The selection is slanted towards active control of fan noise with two papers on the interesting subject of buzz saw noise reduction, one paper on control of fan tone noise using flow induction and one paper on hybrid passive/active treatment for inlet nacelles. In addition, there is one paper on optimisation of interior noise control.
Multi-Science Publishing, 2007. , 71 p.