Noise reduction research on helicopter scissors tail-rotor based on aerodynamic shape of the blade

To mitigate the aerodynamic noise generated by helicopter scissors tail-rotor, a numerical computational method tailored for assessing the aerodynamic noise of such rotors was initially developed and subsequently validated through case studies. This method was then employed to conduct focused research on noise reduction by optimizing the aerodynamic profile of the scissors tail-rotor blades. Enhancements were made to the scissors tail-rotor blade tip shape design, and a comparative analysis of the aerodynamic noise was performed against the baseline scissors tail-rotor configuration. The findings indicate that implementing a blade design featuring swept-forward and swept-back tips results in a noticeable noise reduction, with an overall noise decrease of approximately 2 to 2.5 dB at several key observation points.