Progresses in aviation noise research including noise prediction and noise reduction technologies but also the possibility to transfer research results into application depend strongly on the availability of a suitable aeroacoustic wind tunnel test facility. In addition to small high quality facilities for basic research as for example the Acoustic Windtunnel Braunschweig (AWB) only the very large and expensive DNW-LLF comes into consideration as a high quality test facility for three dimensional wind tunnel models.
|Steady and unsteady wind tunnel corrections|
This situation is critical in view of the aggressive noise reduction objectives for aviation noise defined by the EU for the year 2020, because strongly needed research activities cannot be performed adequate because of missing wind tunnel facilities. Similar objectives were expressed overseas and the availability of a respective experimental tool may become essential for the competitiveness in Europe and in particular Germany in this field.
In recent years noise reduction at transport aircraft has become an ever more demanding task for experimental wind tunnel investigations since not the engines alone contribute to the overall noise of an aircraft but also the turbulent flow past the airframe. Many of the complex aeroacoustic sources are not even understood properly. Anyway, in the future it will not be sufficient to develop and investigate new aerodynamic technologies independent of their aeroacoustic consequences.
To implement this demand and to fill the gap of feasible aeroacoustic wind tunnels the new DNW-NWB has been designed and enters the phase of establishing its qualification.
Also the extension of the competence to determine dynamic derivatives is of vital importance and interest for the new facility with the absolute need of qualification. The configuration selected for this task presents an innovative forward swept wing configuration closely connected to the concept “Forward Swept Wing” essentially contributing also in forward swept wing research.
The DLR project NumEx will contribute within three work packages by investigations aiming at the acoustic qualification, the improvement of aerodynamic and acoustic correction methods as well as the extension of the competence on the field of the experimental determination of dynamic derivatives in the DNW-NWB.
The duration of the project is from Jan. 2011 to Dec. 2013.