Wind tunnel model
The model is unique in the sense that never a wind tunnel model has been equipped with so many balances; a main balance measuring the overall loads on the model, a wing balance measuring the loads on the wing-nacelle substructure, a nacelle balance to measure the nacelle loads, a tail balance to distinguish the loads on the two tails and further control-surface loads (2x aileron, 2x ruddervators, rudder and elevator).
In the trend to always aim for a more accurate load measurement and more accurate remotely controlled positioning of a control surface, new laboratory techniques were put in where possible.
Reynolds number extrapolation and analysis for Tilt Rotors
A novel procedure was applied providing reliable corrections to the wind tunnel data. This was accomplished through extensive CFD calculations covering the complete range of Mach en Reynolds numbers as well as angle-of-attack and side-slip conditions. The range of Reynolds numbers extended from wind tunnel to full scale conditions. This procedure was done for each of the two empennages, resulting in two very detailed sets of correction values to all force and moment coefficients, not just drag and lift. The calculations take into account Reynolds number, Mach number, angle of attack and sideslip, and are specific for the tilt rotor concepts under consideration.
High Speed Machining (HSM)
HSM was used for manufacturing of the fuselage, internal structure and interfaces; except reduction of manufacturing time it can offer a wide range of advantages:
• Cutting force reduction;
• Small heat flow to workpiece, heat transferred into chips;
• Increased quality of manufactured parts;
• Reduction of finishing machining
Moreover, in addition to above features of HSM, it also allow to manufacture more complex shapes and thin walls, what can have impact on final weight of the part or surface fidelity.
By contributing to the optimization of the tail, to be implemented on the Technology Demonstrator, the aerodynamics will be improved and effect the effectiveness of the vehicle.
With high maturity of technology integration aimed at completion of this rotorcraft program including flight demonstrations, the possibility to match ACARE goals (sustainable mobility) with actual products to be subsequently developed will be substantiated.
