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Deharde completes Frigate Ecojet’s aerodynamic model #2 manufacture
01 December 2014
Deharde completed the manufacture of aerodynamic model #2 for Frigate Ecojet aircraft. The model is designed to conduct the aerodynamic tests at the European Transonic Windtunnel (ETW) in Cologne, Germany. The choice of facilities was determined by the capabilities of full-scale aerodynamic testing. Cryogenic wind tunnel testing conducted early in the project is determined by the non-conventional aircraft geometry. The standard methods do not allow estimating the performance level by conventional wind tunnels tests.
The testing program includes the conditions aimed at getting the full-scale aerodynamic performance data with buffet study and minimizing layout components drag. These tasks are typical for testing at high Reynolds numbers in ETW, which is able to provide an analysis of these effects during model tests in the wind tunnel due to the following:
- a wide range of Reynolds numbers (up to full-scale)
- individual changes of the flow performance data to divide the effects of aerodynamics and model deformation
- the highest quality of flight conditions simulation based on a high level of flight conditions frequency in wind tunnel.
- equipment and methods to determine and observe the aerodynamic effects on the surface of models.
- equipment to determine performance data on a particular type of model and suspension rigs particularly the wing deformation, the strut interference and dynamic vibrations of the model.
Besides, the model was designed to determine the effectiveness of the longitudinal and directional control, and to ensure compatibility with the transonic wind tunnel TWT ARA (UK) requirements. A series of model testing in ETW and TWT will provide all the necessary data for recalculating and subsequent activities to improve the aircraft aerodynamics. The above mentioned tests objectives affects the model design initially. Requirements the model structure provided by ETW applies to testing conditions, model equipment and capabilities of different testing methods. A common example is the determination of the maximum dynamic pressure required not only to perform structure analysis but also to determine deformation-induced parts during testing.
The type of facilities and testing program define place exacting demands on the model structure, materials, adjustments quality and surface roughness.
Frigate Ecojet aircraft model manufacturing applied a special cold-resistant cryogenic steel G90C with 160kgs / mm2 breaking strength. Implemented accuracy of model manufacturing model was 0.02 mm for lifting surface under the conditions of roughness of less than 0.2 nm and the complete absence gaps in junctions and joints.
The model testing acceptance procedure performed jointly by Frigate Ecojet, Tyssen Krupp System Engineering, ETW and Deharde Maschinenbau GmbH met all requirements applied to such type’s models.
Frigate Ecojet aircraft model will be the first model of the Russian aircraft tested at the European wind tunnel. For the first time in the history of the Russian aircraft industry full-scale testing results will be applied to such type of aircraft.