(19)
(11) EP 1 995 470 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
08.09.2010 Bulletin 2010/36

(43) Date of publication A2:
26.11.2008 Bulletin 2008/48

(21) Application number: 07012624.8

(22) Date of filing: 27.06.2007
(51) International Patent Classification (IPC): 
F04D 29/66(2006.01)
G10K 11/178(2006.01)
 F04D 29/52(2006.01)
(84) Designated Contracting States:
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC MT NL PL PT RO SE SI SK TR
Designated Extension States:
AL BA HR MK RS

(30) Priority: 27.06.2006 US 805944 P

(71) Applicants:
  • Société de commercialisation des produits de la recherche appliquée Socpra - Sciences et Génie s.e.c
    Sherbrooke QC J1K 2R1 (CA)
  • CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE (CNRS)
    75794 Paris Cedex 16 (FR)
  • Université de Poitiers
    86022 Poitiers Cedex (FR)

(72) Inventors:
  • Gérard, Anthony
    Shebrooke, Québec J1H 1S9 (CA)
  • Berry, Alain
    Shebrooke, Québec J1N 3Z3 (CA)
  • Masson, Patrice
    Shebrooke, Québec J1N 3W4 (CA)
  • Gervais, Yves
    86000 Poitiers (FR)

(74) Representative: Gabriel, Franck 
PROXIP 142 Rue de Rennes
75006 Paris
75006 Paris (FR)

   


(54) Method and apparatus for controlling tonal noise from subsonic axial fans


(57) An apparatus for reducing a selected tonal noise generated by an axial flow fan (12) operating in a non-uniform flow by locating at least one obstruction (2) in the non-uniform flow such that the at least one obstruction (2) generates a noise that is out of phase with the selected tonal noise. The noise generated by the at least one obstruction (2) interferes with the selected tonal noise, thus reducing the selected tonal noise. It is also contemplated to use additional obstructions to reduce other tonal noises generated by the axial flow fan (12).







Search report