Generation of an Advanced Helicopter Experimental Aerodynamic Database for CFD Code Validation (GOAHEAD)

Kurzfassung

During the last ten years considerable progress has been made in the development of aerodynamic prediction capabilities by means of CFD for isolated helicopter components such as an isolated main rotor or an isolated fuselage. Today leading edge CFD software systems are available which are capable of predicting the viscous flow around complete helicopters. The greatest shortcoming in Europe for qualifying RANS methods as design tools in the industrial design process for helicopters is the lack of detailed experimental validation data for the aerodynamics of complete helicopters. This issue was addressed by the European GOAHEAD research project (Generation of Advanced Helicopter Experimental Aerodynamic Database for CFD code validation). The presentation will give an overview over the results obtained in GOAHEAD: Within the project a wind tunnel experiment for a complete helicopter configuration consisting of fuselage, main and tail rotor was conducted. The wind tunnel set-up, the extensive model instrumentation and the wind tunnel test matrix were chosen to satisfy the requirements for validation of CFD methods. Results of the campaign in the DNW-LLF wind tunnel include unsteady pressures and loads, laminar/turbulent transition lines, blade deformation data and flow field visualization by means of PIV. The data were analysed in detail and a comprehensive documentation was generated for the experimental data base. In parallel to the wind tunnel experiment six European CFD codes were applied by 11 partners from industry, research organizations and universities in a blind test and post test exercise. The comparison of the computational results provides an assessment of different code features, allows to evaluate the reliability of the codes and gives directions for further code developments. The progress made within GOAHEAD is a big step forward having in mind that the first successful RANS helicopter simulations in Europe have been published in 2002.