The Akaflieg Darmstadt is a group of students with currently about 30 members. The main purpose is: “research - build - fly“ .
The Akaflieg has been designing and building aircraft at the Technical University of Darmstadt since 1920. These planes are used for research in aeronautic engineering, performance flying and also for flight training. This gives us the opportunity to provide students the possibility to fly and do basic flight training. As part of the design and building process of these aircraft, we develop and test new technologies.
Many students are given the possibility to do further reasearch with their bachelor and master thesis on subjects regarding our research and parts of their work are often used in the commercial manufacturing of aircraft. The Akaflieg Darmstadt has a long standing tradition as one of the oldest student groups at the TU Darmstadt. In 2015, the Akaflieg celebrated its 95th anniversary. Many accomplishments have been achieved during these years and we are proud of our excellent reputation in the gliding community worldwide.
Amongst the many completed projects there are some of special interest:
The gliding and small-aircraft industry is dominated by engineers which were members in an Akaflieg at their universities. Special professional skills, the high practical reference with the ongoing task to solve organizational and technical problems in team work provide a substantial addition to a vocational preparation and the curriculum at universities. The industry benefits from such skills.
Our newest project is the D-45 and its design is in progress. The main goal is to design the first allprepreg build glider in Europe and to do further research on the best way to process the prepreg in the sailplane without the use of a autoclave.
Due to machine production, Prepregs achieves higher fiber volume content and directional precision. Using Prepregs reduces the weight of a structure and achieves a higher strength than the traditional way of working with fibers. However, they must be stored at low temperatures and need high temperatures and pressure to cure. These requirements are the reason why the process is not already implemented at the sailplane industry.
We intend to find a way to efficiently use Prepregs in our construction and build the D-45 as a proof of concept to demonstrate the feasability of such a manufacturing process to the commercial manufacturers.
Preliminary studies and master thesis were made for the mould materials and prepreg systems. The first design of the D-45 is already created in a CAD system. Many CFD simulations for optimizing the first design have already been made. The design for the fuselage is completed by now and the following steps are the design and computing of the canopy and fuselage-wing junction. At the same time, students are working at the airfoils that are used at the D-45.
Having a preliminary design allowed the construction of a life size cockpit mockup to analyze ergonomics. We measured the pilots seating and his view to ensure comfortable, safe and long flights.The results are used to iteratively update every aspect of the planes design in the computer model, for example to ensure that the shape of the canopy not only provides a great view to the pilot, but also has minimal influence at aerodynamic drag.
We are currently creating a CAD design of the controls and the undercarriage in order to implement it in the life-sized mockup in the near future. Furthermore, we are doing calculations to estimate the space needed for special structural elements that
absorb energy in case of a crash and provide a very high degree of safety in case of a crash to the pilot. Once the calculations are completed we will implement these in the full-scale model as well. The wings of the plane have currently left the basic layout phase. Instead of using a current wing airfoil developed by somebody else we designed our own wing airfoil to perfectly match the fuselage to achieve very harmonic flight characteristics.
However, since the main goal of the project is using prepregs as the main structural component the next big step for us is performing various analysis of a wide range of prepreg systems to examine the best and most feasible manufacturing process for the airplane.
We plan on using a prepreg system, which cures at a low temperature, which will enable us to build the plane at our workshop, where we do not have access to an autoclave.