Recent Advances in Rotor Aerodynamic Optimization, Including Structural Data Update

Joëlle Bailly (1) , Biel Ortun (1) , Yves Delrieux (2) , Hugues Mercier Des Rochettes (3)

1 ONERA - The French Aerospace Lab [Meudon]
2 ONERA - The French Aerospace Lab [Châtillon]
3 ONERA - The French Aerospace Lab [Lille]

This study summarizes a rotor blade shape optimization exercise with an emphasis on the risk of off-design performance degradation. After optimizing by comprehensive analysis twist and anhedral with respect to rotor shaft power in a highspeed, high-load forward flight condition, benchmarks against the reference blade were performed on vibratory levels, acoustics in descent flight, and aerodynamic performance. Performance in forward flight and in hover is validated by coupling comprehensive analysis with computational fluid dynamics. In forward flight, the coupled evaluations confirm the comprehensive code predictions of moderate shaft power reduction. In hover, the optimized-for-forward-flight rotor underperforms the reference. Also, higher blade–vortex interaction noise levels occur in descent flight. Next, as a step to evolve toward increasingly feasible optimized designs, a method to update blade structural properties as a function of variations in blade shape is proposed. The method is first evaluated between two real blades of known properties. Second, the method is implemented in a shape optimization loop and assessed for two optimization cases. It is shown that accounting for structural data modifications smoothes the optimal shape and produces more realistic designs, albeit at the cost of a smaller margin in power reduction.

Mots clés: HELICOPTER ROTOR; AERODYNAMIC OPTIMIZATION; STRUCTURAL DATA

Mots clés: ROTOR HELICOPTERE; OPTIMISATION AERODYNAMIQUE; STRUCTURE DONNEES

Domaines: Mécanique des fluides [physics.class-ph]; Mécanique des structures [physics.class-ph]

Joëlle Bailly, Biel Ortun, Yves Delrieux, Hugues Mercier Des Rochettes. Recent Advances in Rotor Aerodynamic Optimization, Including Structural Data Update. Journal- American Helicopter Society, 2017, 62, page 022009-1 - 022009-11. ⟨10.4050/JAHS.62.022009⟩. ⟨hal-01705571⟩