NASA Technical Reports Server (NASA) · 1981 · 46 citations · 0 references
EngineeringAerospace EngineeringMechanical EngineeringAcoustic DesignAcousticsAircraft DesignNoise Reduction DesignPropeller DesignPropeller NoisePropulsion MachineryPropulsion NoisePropulsion SystemsAcoustic Treatment DesignGearbox IntegrationGearbox VibrationMach NumberMaintenance Requirements AnalysisNet GainPropeller Design For Noise ReductionPropeller Noise Reduction
Results are reported of a NASA sponsored analytical investigation into the merits of advanced counter rotation propellers for Mach 0.80 commercial transport application. Propeller and gearbox performance, acoustics, vibration characteristics, weight, cost and maintenance requirements for a variety of design parameters and special features were considered. Fuel savings in the neighborhood of 8 percent relative to single rotation configurations are feasible through swirl recovery and lighter gearboxes. This is the net gain which includes a 5 percent acoustic treatment weight penalty to offset the broader frequency spectrum noise produced by counter rotation blading.