On 2 December 2010, the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) opened the world's most powerful aero-acoustic wind tunnel in collaboration with German-Dutch Wind Tunnels (Deutsch-Niederländische Windkanäle; DNW). Scientists use wind tunnels to investigate the aero-acoustic properties of objects such as aircraft engines and wings. Not only is the Braunschweig wind tunnel one of the most powerful of its kind, but also it is so versatile that it can be used for cars as well as planes. This presents new possibilities in which to record and reduce sources of noise pollution.
Credit: DNW.
With special aircraft, known as Personal Aerial Vehicles (PAV), it will be possible for anyone to carry out daily journeys through the air in the future.
Credit: Gareth Padfield, Flight Stability and Control.
The simulation center is home to a moving and a stationary simulator with an interchangeable cockpit.
Credit: DLR (CC-BY 3.0).
The ACT/FHS 'Flying Helicopter Simulator' of the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) is based on a standard Eurocopter EC 135 type helicopter, which has been extensively modified for use as a research and test aircraft.
Sixty-three mannequins took the place of passengers on board DLR’s Advanced Technology Research Aircraft (ATRA).
The HALO (High Altitude and LOng Range) research aircraft is based on the ultra-long-range G 550 business jet produced by Gulfstream Aerospace. With a range of more than 8000 kilometres, measurements on the scale of continents are possible; the research aircraft can reach all regions, from the poles to the tropics, and remote areas of the Pacific Ocean.
The Falcon is the only research aircraft in Europe that is legally able to fly at high altitudes and over long distances in volcanic ash clouds.
The Eyjafjallajökull volcano in Iceland emitted large quantities of ash and sulphur dioxide into the atmosphere during its eruptions in March and April 2010. This photograph was acquired on 1 May 2010 during a measurement flight by the DLR Falcon research aircraft.
Behind the DC-8, the scientists on board the DLR Falcon measured the exhaust gas composition.
Credit: NASA.
After a research flight, the Falcon is towed past the SOFIA airborne observatory on the way to its parking position.
Despite its wingspan of 72 metres, the lightweight aircraft, with the identification HB-SIB, weighs only about 2.5 tons. Almost half of the weight is accounted for by the cockpit and the four engine nacelles, which have integrated batteries to provide the aircraft with power at night.
Credit: SolarImpulse/Anna Pizzolante/rezo.ch.
The Airbus A320-232 'D-ATRA' (Advanced Technology Research Aircraft) is the largest member of the DLR research fleet.
Credit: DLR/Evi Blink (CC-BY 3.0).
On the first test flight with the 3D special camera, the scientists flew in the vicinity of the 8,091-metre-high Annapurna ( visible in the background).
Blade tip vortices are visible as dark lines during a full rotation of the main rotor. The engine exhaust flows are perceptible as a noisy area trailing the helicopter. The tail rotor's vortex system is also visible (black, circular lines on the tail rotor). The helicopter is currently performing a rocking manoeuvre.
These powerful vortices can disrupt sensitive equipment close to the aircraft's path along a runway and also damage buildings. Smaller aircraft are especially sensitive to the wake vortices created by larger 'jumbo' jets, so they must maintain a greater safety separation.
The DLR Do 228-212 research aircraft in front of the DLR flight operations hangar in Oberpfaffenhofen.
The quantum key transmission experiment took place in Oberpfaffenhofen, using the optical ground station at the DLR Institute of Communications and Navigation and the Dornier Do 228-212 research aircraft. The laser beam sent from the aircraft was received by the ground station, recorded with specially developed measuring equipment and analysed.
For the measurement campaign, a series of microphones were positioned at various places inside the engine and around the exhaust area and recording their signals simultaneously. These signals formed the basis for the acoustic field analysis.
Model of a helicopter rotor blade in the transonic wind tunnel. Air is blown through openings near the leading edge in order to improve the aerodynamics.
The scientists want to predict the maximum lift of aircraft more accurately; future aircraft configurations and high lift devices should provide further aerodynamic improvements.
Aerodynamic analysis of a blended wing body; the colours indicate the pressure distribution.
Air traffic increases in volume by up to six percent every year. To make air travel more environment-friendly and quieter, researchers at the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR), together with partners Airbus, EADS Innovation Works and Cassidian Air Systems, have been carrying out research to reduce the aerodynamic drag of aircraft and have developed an alternative to the traditional leading-edge slat. A morphing leading edge is expected to replace slats to create an innovative high-lift system. This construction significantly reduces air resistance and noise during landing.
The fan blades on the Ultra High Bypass Ratio (UHBR) test system at the DLR Institute of Propulsion Technology.
The rotor test facility at the Institute of Flight Systems.
The world's largest research autoclave is located at the DLR site in Stade.
What looks like a wind tunnel is actually an air intake chamber. Engine researchers use the 16-metre-long, eight metre- diameter enclosure to remove turbulence from air before it reaches the compressor of an engine during testing. This allows them to achieve optimal and repeatable conditions for their experiments.Fans and compressors are important research topics at the DLR Institute of Propulsion Technology by reason of the great influence they exert on the performance of engines and their noise emissions. The researchers are working on new designs for axial and radial compressors, and verifying their multidisciplinary development techniques using prototypes. The multi-shaft compressor test facility, shown in this image being prepared for a test, is essential for this process.
Credit: DAAD / Lannert.
Reduced pressure on the top of the blade draws air upwards; this produces a vortex – the blade tip vortex – that is then directed downwards. When other rotor blades subsequently come into contact with these vortices, the 'chopping' or throbbing noise characteristic of helicopters is produced.
Air flows around a rectangular wing in the 50-metre-long transonic wind tunnel at Göttingen. The wing is then caused to oscillate, as can happen during flight. This leads to turbulence in the airflow, which impacts another, smaller aerofoil that also begins to oscillate.
GroFi - Large-Scale Parts in Fiber Placement Technology is based on independent robotic units for automated production of components made of composite materials
The key to understanding the flying characteristics of insects lies in precise calculation of the airflow velocities behind their wings. To establish this, these creatures are placed in a wind tunnel to enable them to exhibit the most natural flying characteristics possible. To do this, researchers exploit a reflex action; as soon as locusts cease to feel ground under their feet and find themselves facing a headwind, they begin to fly. The locusts and the moths are fixed to small rods with a drop of glue and are then blown at 11 and seven kilometres per hour respectively. This glue is removed from the insects after completion of the tests, without harming them.
A test candidate from the Germany Armed Forces during the first trial of the new helmet mounted display in the generic cockpit simulator at the DLR Institute of Flight Guidance.
Together with its partners Airbus and Lufthansa Technik, DLR has developed an electrically driven nose wheel powered by a fuel cell. This enables aircraft to move to the runway – or to taxi to their stand – without using their engines. This development can help to significantly reduce pollutant and noise emission. Studies have shown that about 20 percent of the emission of pollutants such as nitrogen oxides and carbon dioxide produced during ground operations at an airport can be avoided. In an initial test conducted in 2011 using the DLR A320 ATRA research aircraft, this nose wheel proved that the electric drive is capable of moving transport aircraft of this size.
The laser sensor of ALLFlight (Assisted Low Level Flight and Landing on Unprepared Landing Sites) is integrated into the small box below the helicopter. In the framework of DLR's ALLFlight research project, scientists are developing a system to generate a digital map for the cockpit and assist the pilots in difficult situations - up to a fully automated landing.
At DLR Göttingen, the air flow in the aircraft cabin is made visible with laser and fog particles. The main obejctive of these studies are to increase passenger comfort.
Claus Wahl, a DLR scientist in the Chemical Analysis Department, working on a mobile measuring device to analyse exhaust emissions and measure particulates generated by 'Gas to Liquid' (GtL) fuels. In modern combustion research, chemical and instrument analyses are indispensible in analysing the emissions from combustion processes and deriving measurements to reduce pollutants.
Tests have already been carried out on models of the Airbus A380 in the Cologne Cryo-Tunnel (Kryo-Kanal-Köln) – and on German Aerospace Day visitors will get to see an Alpha Jet model. Here, complete models, half models or wing profiles are exposed to wind speeds of up to Mach 0.42 (over 500 kilometres per hour).
The flight of birds is still largely unexplored; in particular, the movements performed during the beat of a wing and the airflow around the wing remain a puzzle to scientists. The German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR), in collaboration with RWTH Aachen University (Rheinisch-Westfälische Technische Hochschule Aachen) and the German Armed Forces University in Munich (Universität der Bundeswehr München) is addressing this question. Starting on 26 April 2011, the scientists will be photographing the wings of an owl while in flight inside a closed room at RTWH Aachen University to obtain information about the how the shape of the bird’s wing changes during flight. This calls for basic research. Since the launch of the project in 2008, the team of scientists has succeeded in studying owl wings during gliding flight; the forthcoming measurements will be focussing on the wing beat phase.
Thanks to its optical and electronic control system, the FHS can simulate the flight behaviour of other helicopters.
Numerical simulation: Simulated pressure distribution for an airliner in landing approach.
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