Technical article 2022

Here you will find articles from our research.

Scientists of the Institute of Aeroelasticity regularly give short insights into their work.

fs35 Harpyie - Ground Vibration Test for full certification
December 15, 2022

fs35 Harpyie - Ground Vibration Test for full certification

In October 2022, the Ground Vibration Test (GVT) of the fs35 Harpyie motor glider took place at our structural dynamics laboratory in Göttingen. For two weeks the aircraft of the student research group Akaflieg Stuttgart has been tested extensively.

Earth observation - aeroelasticity for the design of the High Altitude Platform HAP
November 18, 2022

Earth observation - aeroelasticity for the design of the High Altitude Platform HAP

The High Altitude Platform (HAP) is a very light weight, high altitude and long endurance aircraft (HALE) designed to stay airborne and hold position for several days at an altitude between FL450 and FL800 (≈14 to 24 km, above normal air traffic). Carrying optical measurement equipment (up to 5.0 kg), this allows scientists to make observations of the earth continuously for a long period of time. This is an advantage compared to satellites, which typically pass the same spot only every couple of days and fly much higher, leading e.g. to a lower optical resolution.

Proven principle new shape - Why rotor blades have a kink
November 3, 2022

Proven principle new shape - Why rotor blades have a kink

From the beginning, Helicopters always have rotor blades with a simple rectangular planform. This worked and had proven as the typical helicopter rotor blade principle. But if the rotor blade planform will changed, rotor noise and vibrations can be significantly reduced, while enhancing the aerodynamic efficiency.

Rigid helicopter rotor blades – Is this really enough?
July 14, 2022

Rigid helicopter rotor blades – Is this really enough?

Specially shaped helicopter rotor blades with a kink at the outer part make it possible to reduce the radiating annoying rotor noise [1]. Against this background, the aeroelastic behaviour together with the aerodynamic phenomenon of dynamic stall is of great importance.

Acceleration sensors for wind measuring mast at the DLR research windfarm (WiValdi)
July 6, 2022

Acceleration sensors for wind measuring mast at the DLR research windfarm (WiValdi)

For the DLR research windfarm (WiValdi) two multi-megawatt wind turbines are currently built in Krummendeich. They will be both instrumented with innovative research sensors. To characterize the wind field there is already a 150m high IEC conform wind measurement mast available besides others like lidars that will be installed on the wind turbines.

Revolutionary aircraft concepts: A new stress test for engines
May 6, 2022

Revolutionary aircraft concepts: A new stress test for engines

Recently, many new concepts for future emission-free aircraft have been presented. On closer inspection aircraft manufacturers are also relying on new integration concepts for the engines. The result is that engines suck the boundary layer from the aircraft fuselage. For the aircraft as a whole, this reduces drag, which potentially reduces fuel consumption. At the engine level, however, the disturbed inflow poses challenges to both aerodynamic operational behavior and structural dynamic design.

CO₂-neutral flying - how can aeroelasticity contribute to this?
April 20, 2022

CO₂-neutral flying - how can aeroelasticity contribute to this?

In the future, aircraft will have to fly in a much more environmentally friendly manner in order to contribute to meeting the targets for limiting global warming. With the aim of testing new innovative engines, DLR has added a new research aircraft, a Do228-202, to its fleet. On this aircraft, electric engines powered by a hydrogen fuel cell are to be tested.

Aircraft Configurations with Distributed Propulsion – Effects on Loads, Structural Mass, and Aeroelasticity
March 18, 2022

Aircraft Configurations with Distributed Propulsion – Effects on Loads, Structural Mass, and Aeroelasticity

The concept of distributed electric propulsion units has great potential on the track to zero-emission aircraft. Investigations raise expectations that distributed propulsion engines improve the aerodynamic performance, flight mechanical aspects as well as the aircraft loads. Reduced loads will lead to a reduction of the structural weight. Besides environmental aspects, the physics and technical based aircraft characteristics are of great importance.

Semi-active flutter suppression
February 25, 2022

Semi-active flutter suppression

The term flutter represents one of the central phenomena in the field of aeroelasticity and describes a self-excited oscillation, which, in the worst case, can lead to a destruction of aircraft components and ultimately to a destruction of the aircraft itself. Especially in the transonic flow regime, the risk of flutter is high. Hence, the design process of an aircraft has to emphasize on preventing such critical conditions. Measures to control the flutter behavior are an important field of research in aeronautics. One possible approach is the use of spoilers.

New Methods to Analyze the Aeroelastic Stability of Future Lightweight Aero Engine Blades
February 11, 2022

New Methods to Analyze the Aeroelastic Stability of Future Lightweight Aero Engine Blades

To increase the efficiency and overall performance of aircraft engines, larger fan diameters and higher bypass ratios are consistent trends. An associated technical requirement is lightweight design. The solutions are lighter materials like aluminum or composite (carbon-fiber reinforced plastics, abbr. CFRP) and hollow blades.These lightweight constructions require new methods to safely analyze the aeroelastic stability.

No more vibrations! - Viscoelastic damping design for the reduction of aircraft vibrations with elastomers
January 27, 2022

No more vibrations! - Viscoelastic damping design for the reduction of aircraft vibrations with elastomers

Anyone who has ever flown in an airplane knows this problem: You want to read a book or to snooze without being disturbed, but around you there is an annoying bucking and a humming noise. The sources of these disturbing events are usually wing or fuselage vibrations which are amongst others caused by wind gusts, turbulence or by engine operation. Do passengers have to keep on suffering from the negative consequences of such vibrations in the future? Or is there any prospect of improvement?

How can an aircraft save weight and have a longer service life by deflecting the control surfaces?
January 13, 2022

How can an aircraft save weight and have a longer service life by deflecting the control surfaces?

In aircraft research, the reduction of the structural mass is a core aspect since it helps in decreasing the fuel consumption and thus the CO2 emission. The structure itself is designed to withstand the loads on the aircraft. Hence, if the loads can be reduced, the structure can be built lighter. However, in doing so, the requirements of the certification specifications still have to be fulfilled.