Rotor blade for wind turbine

In this project the structure of a rotor blade for a small wind turbine (SWT) was developed for the renowned German sailplane manufacturer DG-Flugzeugbau. This SWT specifically designed for low wind conditions has a rotor diameter of 13 m and delivers an output of 10 kW already at wind speeds of 7.5 m/s. within only 5 months and in cooperation with the specialists from DG-Flugzeugbau, HD-Composite and Steinbeis Flugzeug- und Leichtbau GmbH, a completely new structural design approach was realised which reduces the production cost by 75% compared to the original blade! At the same time the weight of the rotor blade could be reduced by 30% which itself contributes already to cost reduction.

For the composite structure of the rotor blade, Karl Käser prepared the load assumption and then strength analysis and chose suitable materials with respect to cost and production optimisation. Furthermore Karl Käser contributed essentially to the development of the new structural design and delivered support for mould design and production and in certification questions. For the design of the laminates MicMac ® of Professor Tsai was used and the CAD work was executed in Catia V5 in cooperation with Steinbeis Flugzeug- und Leichtbau GmbH. Due to the good baseline work, first and second eigenfrequencies of the rotor blade could be determined in advance with an accuracy of 5% compared to the ready produced blade. The rotor blades are installed to the SWT TN535 of Tozzi Nord which is now already MCS certified by NQA.