Nowadays helicopters play a pivotal role in a wide variety of activities from important military missions to emergency medical transport, indeed it is a common experience that a helicopter may often be seen overhead. Originally, aircraft noise was not much of an issue because of the overarching requirement of improving vehicle performance in critical operational conditions. By the 1960s, noise and vibration control of helicopters has become more and more important and the next level technical challenge is to include new design parameters such as vibro-acoustic comfort and environmental impact in the design process of a modern rotorcraft. From one side, government regulations are imposed to contain noise pollution while on the other hand customers do not accept any longer a noisy product. On top of all this, the competitive pressure to bring products faster to market has made that NVH (Noise Vibration and Harshness) designers are looking for tools giving them an insight on where the noise is coming from. In this scenario, we want to present a modus operandi to tackle this issue by several advanced experimental methodologies, since the requirement of a quieter helicopter needs a systematic study of its NVH behavior. Experimental tests are carried and results are reported concerning two different helicopters: an EUROCOPTER EC-135 and an Agusta Westland W-109 helicopter. The proposed methodologies count several experimental NVH analyses and processing, which will be outline hereafter. It is interesting to note that although the presented methodologies concern particular helicopters, they have a general meaning, since they can be applied in a large variety of fields, as in aircraft fuselage, car or track interiors , etc. This work has to be intended as an analytical review of the authors’ research.
Advanced vibro-acoustic techniques for noise control in helicopters
MUCCHI, Emiliano;
2012
Abstract
Nowadays helicopters play a pivotal role in a wide variety of activities from important military missions to emergency medical transport, indeed it is a common experience that a helicopter may often be seen overhead. Originally, aircraft noise was not much of an issue because of the overarching requirement of improving vehicle performance in critical operational conditions. By the 1960s, noise and vibration control of helicopters has become more and more important and the next level technical challenge is to include new design parameters such as vibro-acoustic comfort and environmental impact in the design process of a modern rotorcraft. From one side, government regulations are imposed to contain noise pollution while on the other hand customers do not accept any longer a noisy product. On top of all this, the competitive pressure to bring products faster to market has made that NVH (Noise Vibration and Harshness) designers are looking for tools giving them an insight on where the noise is coming from. In this scenario, we want to present a modus operandi to tackle this issue by several advanced experimental methodologies, since the requirement of a quieter helicopter needs a systematic study of its NVH behavior. Experimental tests are carried and results are reported concerning two different helicopters: an EUROCOPTER EC-135 and an Agusta Westland W-109 helicopter. The proposed methodologies count several experimental NVH analyses and processing, which will be outline hereafter. It is interesting to note that although the presented methodologies concern particular helicopters, they have a general meaning, since they can be applied in a large variety of fields, as in aircraft fuselage, car or track interiors , etc. This work has to be intended as an analytical review of the authors’ research.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
