Numerical noise prediction and source identification of a realistic landing gear

Noise predictions of realistic landing gear configurations are obtained combining high-fidelity CFD simulations and the Ffowcs Williams–Hawkings (FWH) acoustic analogy. The aeroacoustic prediction such a complex aeronautical system depends on geometry fidelity ability mesh numerical method to resolve important flow features responsible for noise generation. To understand role small components in far-field predictions, different setups analyzed including detailed full complexity simplified, yet realistic, configuration. For latter case, two terms resolution topology analyzed. finer mesh, refinement is applied regions with strong pressure fluctuations also close edges where shear layers develop instabilities. We compare by installed aircraft those computed only setup bottom half fuselage. An assessment solutions from solid permeable FWH surfaces presented surfaces. One objective this work consists identification analysis sources gear. task, we first employ analogy individual identify potential tonal noise. Then, proper orthogonal decomposition mechanisms generation at specific frequencies. It shown that turbulent coherent structures towing link, wheel cavities compartment. external cavity wheel, Rossiter mode excited leads resonance. demonstrate removing small-scale affects characteristics inside compartment and, consequently, its emission. In presence scale eddies generate more higher These scales reduce coherence larger structures, reducing amplitude low frequency band spectrum.