Several complementary technology streams were selected after the initial technology review and corresponding technologies are under development, as described here after.
Rotor hub cap optimisation
The hub cap covering the rotor head allows significantly reducing the drag of hub mechanical parts and mitigate tail shake problems.
Current optimisation studies which rely on most recent CFD tools focus on three different hub configurations, each of them relevant to a specific weight class. Impact on the full aircraft behaviour and performance benefits will be checked with wind tunnel tests and flight demonstrators (target: TRL 6). The complexity of aerodynamic grids for hub mechanical parts is illustrated on. Two consortia of partners (CARD led by University of Glasgow; HELIDES led by CFD_software GmbH) contribute to this work. The diagram on the right shows an unstructured grid for EC135 main rotor hub.
Passive and active flow control devices
Passive and active vortex generators are investigated as means to delay the flow separation on the aft part of blunt fuselages. Testing is planned using wind tunnel models (target: TRL 4).
Separation on blunt fuselages can alternatively be controlled by air jets (synthetic or pulsed jets). This advanced technology is investigated by numerical simulation and wind tunnel tests (target: TRL 4).
The specifications are derived from full helicopter dynamic simulation and system performance will be checked in the wind tunnel on a 1:4 scale GOAHEAD project tail unit.
Optimised helicopter geometry
The possibility of combining drag reduction technologies to produce a range of optimised helicopter fuselages tailored for different aircraft sizes and architectures is addressed using CFD (three configurations). The validation is performed in the wind tunnel for a light helicopter - the ADHeRo partner University of Munich contributes to this work – and for a heavy helicopter platform whose baseline design is close to the GOAHEAD model (target: TRL 4). The diagram on the left shows an optimised geometry for tilt rotor A/C.
Optimised geometry for tilt rotor A/C
Similar work is planned for the ERICA tilt rotor based on the NICETRIP reference (targeting TRL 4). The CODE-Tilt Partner Consortium led by University of Padova contributes to this work.
Optimised engine inlet & exhaust for helicopters
Enhanced engine installations for improved performance
and lower noise are designed for two configurations: light and heavy helicopters. Both wind tunnel and flight tests will validate the solutions (target: TRL 6). The Partner Consortium HEAVYcOPTeR led by University of Padova contributes to this work.
Optimised engine inlet and exhaust for tilt rotor
A similar effort is conducted in collaboration with the TILTOp Partner Consortium (led by University of Padova) addressing the integration of the engine in the ERICA nacelle, leading to validation by wind tunnel tests (target: TRL 4).