Reduction of Flap Side Edge Noise - the Blowing FlapA technique to reduce the noise radiating from a wing-flap side edge is being developed. As an airplane wing with an extended flap is exposed to a subsonic airflow, air is blown outward through thin rectangular chord-wise slots at various locations along the side edges and side surface of the flap to weaken and push away the vortices that originate in that region of the flap and are responsible for important noise emissions. Air is blown through the slots at up to twice the local flow velocity. The blowing is done using one or multiple slots, where a slot is located along the top, bottom or side surface of the flap along the side edge, or also along the intersection of the bottom (or top) and side surfaces.
Document ID
20110016461
Acquisition Source
Langley Research Center
Document Type
Other - NASA Tech Brief
Authors
Hutcheson, Florence V. (NASA Langley Research Center Hampton, VA, United States)
Brooks, THomas F. (NASA Langley Research Center Hampton, VA, United States)