Morphed vertical tailplane assessment for certification requirements
The appearance of new materials and smaller and more capable actuators enable the morphing controlled deformation of the aerodynamic shape of wing like type of structures. This contribution presents the studies and conclusions of incorporating a novel morphing rudder for a commercial transport aircraft from the certification conditions perspective. The fin and morphed rudder aerodynamics characteristics have been CFD modelled, and the results obtained point out the efficiency of the VTP design in engine-out scenario when improved with the morphed rudder. The lateral force developed by the morphed rudder is 16% higher than the conventional one for the same overall deflection. The studies also confirm that feasible morphing rudder architectures are achievable through new 3D printing materials and processes, see figure 2. The weight impact of these solutions is negligible in front of the aerodynamic benefits. A commercial transport aircraft 100 passengers, two engines- low wing podded, has been modelled by means of a Matlab code for lateral- directional stability studies under engine-out conditions. The aircraft key parameters are included in Table 1. The engine out condition is considered at critical take off speed, sea level conditions (air density 1.237 Kg/m3), Mach 0.25 and aircraft velocity 85 m/s. Table 1. Reference aircraft key parameters. The maximum rudder deflection is set to 30º and the aircraft bank angle to 5º, for both configurations. The engine-out stable flight aircraft required slippage angle, , for the original and the morphed configurations are obtained by means of the aforementioned Matlab code. The available yaw moment coefficient is analysed for both configurations resulting on an increment of 8 %. Therefore it is concluded a decrease of 4% the aircraft minimum control speeds as defined in reference . These results indicate that further studies are required for cruise conditions and rest of mission scenarios in order to assess the introduction of the novel morphing rudder on the aircraft, especially for the potential benefits in EROPS operations for twin engine airplanes.