Periodic Reporting for period 3 - CA3TCH (Comprehensive Aerodynamic-Aeroacoustic Analysis of a Trimmed Compound Helicopter)
Okres sprawozdawczy: 2018-12-01 do 2020-05-31
For the aerodynamic, aeromechanic and aeroacoustic simulation and analysis of the complete configuration IAG has been selected as the sole partner having shown unrivaled competence in rotorcraft simulation capability and capacity in Europe. Primary objective of the CA³TCH (Coupled Aerodynamic-Aeroacoustic Analysis of a Trimmed Compound Helicopter) project in general is the de-risking of the LifeRCraft configuration in the development process, identifying potential problems in aeromechanics, aerodynamics and aeroacoustics before first flight, in order to initiate appropriate countermeasures as early as possible.
The project in total was a great success technically, continuously supporting the topic leader with new insights and valuable information regarding the significance of impeding aeromechanic risks.
In another work package acoustic analysis of the rotorcraft started with focus on interference phenomena between the main rotor and propellers and the interaction of the sound generated there with the airframe. The tool chain has shown the capability to represent proper directivities due to shading and reflection effects, and the post-processing of aerodynamic results is quite straightforward.
In total more than a hundred million core hours of computing time have been utilised for over 50 flight states covering the most interesting parts of the full flight envelope. The second reporting period has seen some tool chain enhancements, improving computational efficiency by utilizing automatic mesh refinement and more conservative load evaluations. In addition, several simulations on the X³ demonstrator validated the computational framework for compound helicopters. For the RACER configuration itself, after another loft update many new flight states were run and analyzed aerodynamically as well as acoustically, pinpointing the topic leader at areas requiring more attention and eventual optimization opportunities.
For dissemination, three presentations were held at AHS conferences and another one at the European Rotorcraft Forum in Delft, The Netherlands. The latter one was recognized with the Gareth Padfield Best Young Paper Award for its outstanding contribution to the field of rotorcraft aeromechanics. Another contribution for this year's AHS conference has been accepted, but shifted to October due to the Corona pandemia. Three articles have been published in reviewed journals (2*AHS Journal, 1*CEAS Aeronautical Journal), another one accepted for publication in the AHS Journal. This year's AHS conference paper is intended to be published as an article in the AHS Journal as well, and the tree PhD candidates having worked on the project are currently busy finalizing their dissertations on the findings and insight from the CA³TCH project. The extended tool chain has been implemented at and licensed to Airbus Helicopters, the Topic Leader.
Looking back, the simulations run and analyzed within CA³TCH have given interesting insight into the peculiarities of this novel compound configuration and provided the topic leader ample opportunity to add this knowledge to engineering judgement on several levels and thus complement other approaches. The capabilities of the extended framework allow for detailed investigations early on, which would otherwise sometimes necessitate flight tests and thus delay information backflow into the development process."