Numerical Investigation and Validation for Open Rotor Hover Performance

The aerodynamic performance of two open fan configurations is investigated and compared using Computational Fluid Dynamics analysis. Two open fan systems based on NACA0012 and NACA64-212 platforms are investigated, where the first fan is modeled at three different rotational speeds and the second fan is modeled at three different blade twists. Aerodynamic characteristics and hover performance are evaluated for both open fans over a range of collective angles. Numerical simulations indicate that the blade chord length has a significant impact on the formation of laminar and turbulent boundary layers on the fan surface, and thus the hover characteristics especially at high thrust levels. Computational results for the NACA0012 open fan are validated with the wind tunnel test data, indicating that thrust and power characteristics has been correctly predicted using the current turbulence modeling method.