Aircraft noise

Aircraft noise is typically aero-acoustically generated, originating from the engines and from turbulence created by the airframe and landing gear. For operators and manufacturers, low noise emissions are key, as landing fees are driven by the ACI noise rating indices.

Akustikdoktorn has qualified experience from aircraft design work at Bombardier Aerospace comprising several projects focusing om interior noise modelling and control as well as source characterization using advanced array measurement techniques.

Noise mapping at airports is performed through our partner Akustix Sp. Zo.o.

Airport noise control

Noise around airports causes major psychological stress and leads to substantial cost for mitigation measures. For airports and authorities there is a need to minimize disturbance from landing and departing aircraft, e.g. by optimizing flight paths. The degree to which people experience aircraft noise has a lot to do with atmospheric conditions. Temperature, wind speed and direction, humidity, rainfall and cloud-coverage have all a part to play in the way we hear aircraft noise.

Airport noise assessments are made to monitor and control the levels that people are exposed to. The exposure is typically calculated using integrated models to present the so-called footprint of aircraft, or rather a yearly average of all the aircraft starting and landing at an airfield.

We can make predictions using e.g. the Integrated Noise Model (acc. to ECAC.Doc 29) for the yearly exposure based on statistical data on flight movements.

Experience and qualifications of our partner Akustix:

  • Noise modelling using INM for civil and military airports (> 10),
  • Noise mapping including aircraft noise: four cities with more than 500 000 inhabitants
  • Noise Action Plans – two airports (Warsaw, Cracov)
  • PCA (ILAC – MRA) accreditation for computational methods

Interior noise

Interior noise in aircraft originates from the engines and the turbulence around the fuselage. Also, the ECS system noise may be a critical for the perceived acoustic comfort by passengers. The transmission to the interior is strongly affected by the fuselage layout, in particular for composite structures, and careful design of the thermal and acoustic insulation is critical to success.

We have qualified experience of modelling interior sound transmission for al and composite fuselage structures and in optimizing structural layout as well as noise control treatments like foams and damping layers with respect to weight and noise. We also have worked on designing ECS systems with respect to air flow and noise generation. Here the detailed lay-out of the distribution nozzles is key, as well as balancing the flow velocities.