Design and Testing of Low Noise Landing Gears

In the approach phase of large commercial aircraft, airframe noise – and in particular that from landing gears – is one of the dominant aircraft noise components. Within a European co-financed research project entitled “Significantly Lower Community Exposure to Aircraft Noise” (codenamed SILENCER) a study in “advanced low noise landing gear design” was performed to develop operational landing gears which take into account aeroacoustic constraints early in the design stage. Airbus aircraft typical configurations of low wing with underslung engines and A340 type gears were selected as reference. RANS flow field calculations were performed and used to identify and thus avoid the impingement of high speed flow onto critical gear structure elements. The evaluation of CFD results with respect to the effects on aerodynamic noise was performed on the basis of related experimental experience and a semi-empirical landing gear noise model. Both low noise advanced nose and main landing gears were designed and manufactured at full scale for noise testing in the 8 m by 6 m open test section of the German-Dutch Wind Tunnel (DNW-LLF).