The US aerospace agency NASA and the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) have signed two agreements on further scientific cooperation in the aeronautics sector. Both partners want to work together on the research topics of aircraft noise simulation and the improvement of helicopter aerodynamics.

The agreements were adopted at the Paris Air Show in Le Bourget during a bilateral meeting between the DLR Executive Board Member for Aeronautics Research, Rolf Henke, and the NASA Associate Administrator for the Aeronautics Research Mission Directorate, Jaiwon Shin.

“In recent years, we have brought our scientific strengths together in several projects, including joint research flights for more efficient and environment-friendly aircraft.” said Henke. “We are now expanding this successful collaboration into the research areas of aircraft noise and rotor craft.” In December 2010, DLR and NASA laid the foundation for collaboration in aeronautics research with a framework agreement.

“NASA and DLR have had a successful research relationship for many years now,” said Shin. “These agreements will ensure that productive collaboration continues as we work together solving challenges that will benefit a global aviation community and flyers worldwide.”

One of the now closed agreements relates to cooperation in the field of sophisticated noise prediction models and establishing standards to enable comparisons between the two research institutions. A reduction of aircraft noise without adversely affecting the environment and efficiency in the aviation sector is a major challenge. This needs to be solved to enable further growth of air transport in the face of more stringent environmental regulations. One of the key technologies for reliable noise prediction during new development takes into account all sources of aircraft noise and the impact of their installation.

Under the joint agreement, both research institutions will generate highly accurate noise predictions for two virtual aircraft configurations – a model of an aircraft with overwing turbofans and another with turbofans under the wings. As the basis for noise prediction, acoustic measurement data will be used; this was acquired by DLR in previous scientific flights with its now decommissioned Advanced Technologies Testing Aircraft System (ATTAS), a VFW 614.

The second agreement relates to the development of a new imaging technique to study the airflow over the rotor blades of a helicopter in flight. NASA and DLR scientists want to find out exactly where on the rotor blades the flow becomes turbulent and the lift weakens. The new imaging technique should also help to determine the structure of the main rotor tip vortices in forward flight in detail.

These agreements are a further step in the now traditional cooperation between DLR and NASA. Both institutions pursue their research with the goal of environment-friendly and efficient future aviation – with low emissions as well as increased safety and efficiency.

NASA and DLR have already cooperated on numerous activities, such as human spaceflight, space exploration, aeronautics research, climate research and Earth observation. Both partners are also working together, for example, on the Stratospheric Observatory for Infrared Astronomy (SOFIA) and the Gravity Recovery and Climate Experiment (GRACE) satellite mission.

Last year, NASA and DLR flew – together with the Canadian National Research Council (NRC) – the ACCESS II (Alternative Fuel Effects on Contrails and Cruise Emissions) research campaign. For this, the DLR Falcon research aircraft and NASA’s DC-8 and Falcon flew from the NASA site in Palmdale, California. The aim was to study the emissions and contrail formation during the use of alternative fuels in flight. The cooperation with ACCESS II took place under the umbrella of the International Forum for Aviation Research (IFAR), in which DLR, NASA and NRC are three among 26 member institutions. IFAR is an active forum of leading international aerospace research organisations. DLR, together with NASA, plays a major role in IFAR.