Infrastructure

The Department of Fluid Mechanics and Aerodynamics operates two Grob G109b motorgliders for research and teaching activities.

The Grob G 109b is a two-seated touring motorglider with controllable pitch propeller manufactured by Grob Aircraft AG.

Both aircraft have been modified in order to meet special requirements of research and educational flight operation.

Due to its design as a powered glider, the G109b is particularly suitable for research flights to study laminar-turbulent transition.

Here, the effect of various influencing factors on the flow around the aircraft under real atmospheric conditions is investigated.

Friction forces in the boundary layer above the airfoil surface accounts for a large proportion of the total drag of an aircraft. The magnitude of the frictional drag is largely determined by the position of the transition from the low-drag laminar boundary layer to the higher-drag turbulent boundary layer. Research activities of the SLA group focus on gaining a better understanding of the laminar-turbulent boundary layer transition to derive methods to manipulate transition. Passive and active methods of flow control are considered.

In addition to the research activities, teaching activities also take place at the August-Euler-Airfield in terms of bachelor and master theses within research projects as well as in the form of student internships. The second G109b is available for student practical courses, which complement the lectures “Aerodynamics 2” of SLA as well as the lecture “Flight Mechanics” of the department Flight Systems and Control Engineering. The aircraft is equipped with measurement equipment specifically developed for this purpose, which allows students to practically deepen their theroretical knowledge.

August Euler Airfield

August Euler Airfield is an approved scientific air field with the designation EDES. The airfield is used to conduct flights according to visual flight rules (VFR) during daytime and for research purpose. The Institute of Fluid Mechanics and Aerodynamics operates its two motorized powered gliders at the airfield.

Airfield data:

Pavement: Asphalt
Direction: 07/25
Length: 1155m
Width: 21m

We have a hangar (20 x 25m) for the storage of the two aircrafts on the airfield.

In the tower building, which is located directly at the airfield, there is an office with equipment needed for flight operations, several meeting rooms of different sizes and an exhibition about the history of the August Euler airfield.

Constant Temperature Anemometry (CTA)

Hot-wire probes offer the possiblity to determine flow velocities with a high temporal resolution, as is necessary for unsteady effects or measurement of degrees of turbulence. CTA techniques use very fast control loops to keep the sensor at an average constant temperature.

Particle Image Velocimetry (PIV and µPIV)

Particle Image Velocimetry (PIV) is a non-instrusive optical technique to determine velocity fields: The fluid is seeded with particles and photos are taken at short intervals. From the particle positions the direction and velocity can be calculated. The Institute SLA has PIV and µPIV (for flow measurements in micro channels) systems.

Laser-Doppler-Anemometrie (LDA)

The Laser-Doppler technique is based on determining the Doppler shift of the light scattered by a moving object that is illuminated by a laser. As the frequency of the light cannot be measured directly, it is brought to a range of several MHz by a reference beam.

Laser-induced Fluorescence (PLIF)

PLIF techniques are based on the fluorescence of a species excited by a laser and are a reliable method to visualize flow or measure species concentrations and temperature.

Phasen-Doppler-Anemometrie (PDA)

The Phase Doppler Anemometry (PDA) systems at the Institute are used to measure the size, velocity and concentration of spherical particles, droplets, or bubbles suspended in gaseous or liquid flows.

Shadowgraphy

The Institute SLA has systems to measure the size and velocity of particles with the help of a special background illumation and an image analysis software.