D-45

Introducing The D-45

After our last successfull prototype – D-43 – had completed its maiden flight, Akaflieg members set out to outline a follow-up-project: The D-45.

After numerous concepts had been evaluated, it was agreed upon that a 15 m racing class glider made up primarily of Prepreg would be the next major project. Prepreg is a fairly novel material and allows for particulary lightweight construction not yet present in european gliders.

The two main challenges were:

  • Choosing a suitable Prepreg system, designing construction blueprints and licensing Prepreg for gliders with the German Federal Aviation Administration
  • Designing an aerodynamic layout that fully utilizes Prepreg’s unique characteristics to make for a lightweight conventional glider

Our current goal ist to work on solving both of these main challenges, possibly via diploma theses of Akaflieg members. For the first time ever in Akaflieg history this plane will be designed solely using computers: The entire design process including all technical illustrations will be digital. Additionally, TU Darmstadt has lent us a CNC milling machine, enabling us to produce our own components as well as moulds.

Key parameters:

  • Wingspan 15m, with option to reduce to 13.5m
  • Prepreg construction
  • Empty weight ~200 kg
  • Wing loading 35-63 kg/m²
  • Aspect ratio ~31-32

A fully parameterised hull shape has already been designed using Siemens‘ NX10 CAD software. All parameters can be adjusted using an Excel sheet. This allows for optimising both aerodynamic as well as ergonomic quality to ensure long and comfortable flights.

CFD simulations will help to optimise fuselage waisting, both 2D and 3D models have already been constructed.

Eventhough the D-45 already features multiple new approaches to glider construction, there are plenty more technologies like boundary layer suction that could theoretically be implemented.

Our new all-digital approach to design and documentation allows for both higher efficiency and well-structured nad comprehensible data to be used by future Akaflieg generations.