The IDOHAP proposal was for the detailed design of two CROR models to be installed on an existing wind tunnel test rig. Each model was comprised of a pair of hubs and associated propeller blades. This work was achieved using design engineers experienced in the design of complex wind tunnel models and associated test rigs, using the Catia V5 (V16) software package. These model designs were required for CROR tests planned in the coming years using an existing CROR powered wind tunnel test rig. The IDOHAP proposal was fully compliant with the topic Call Text.
The European aeronautical industry faces the challenge to counter the environmental impact due to the expected growth of air transport with low fuel burn innovative products. Increasing the by-pass ratio of turbofan engines was a successful measure in the past decades.
The ultimate in this sense is the counter rotating open rotor (CROR) which offers a potential of 20% fuel burn reduction relative to the classical turbofan engine in service today. There is a need to obtain comprehensive knowledge on the aero-acoustic behaviour of CROR blades through experimental characterisation.
Within the European community, CROR tests planned in the coming years will be conducted by means of CROR powered wind tunnels models. In particular, one-fifth- and one-sixth-scale rig testing of installed CROR systems will be performed.
To support this programme, IDOHAP hub designs for a CROR rig have been delivered by the Aircraft Research Association (ARA) located in Bedford, United Kingdom (UK) to Airbus. To insure that rig interfaces were correctly maintained and controlled, the hub designs were researched and developed in close collaboration with the Office National d'Etudes et Recherches Aerospatiales (ONERA) and the Nationaal Lucht-en Ruimtevaarlaboratorium (NLR) who were responsible for the design of the CROR rig and propeller blades respectively.