Predicting turbulence in helicopters
Modelling turbulent flow is always a trade-off between sufficiently accurate descriptions and computational resources. Scientists employed a new family of hybrid models for an optimal mix of solution fidelity and computational cost with the EU-funded project ‘Helicopter drag prediction using detached-eddy simulation’ (HELIDES).Cutting-edge detached eddy simulation (DES) models of turbulent flow around the rear fuselage and rotor hub of a helicopter were compared to pure modelling. For this purpose, Reynolds-averaged Navier-Stokes (RANS) equations and unsteady RANS (URANS) methods were used. Wherever possible, results were compared to experimental data. DES methods were superior to URANS in all conditions and configurations tested. Researchers also performed calculations to predict the technology’s readiness level for industrial usage based on computational time and efficiency. Results showed that they will indeed be ready in the near future.Enhanced ability to predict the conditions and mechanisms of development of highly turbulent flow will facilitate early testing of drag reduction techniques in preliminary design stages. Facilitating the design of future rotorcraft for reduced drag and fuel consumption will have major impact on the environment and the competitiveness of the EU aircraft industry. Finally, computation-intensive DES methods will find a broad range of applications and pave the way to adoption of these powerful techniques in the EU and beyond.
Keywords
Turbulent flow, helicopter, detached eddy simulation, industrial readiness
