Numerical investigation of the noise characteristics and localization of aeronautical pitot tubes during cruise conditions of large civil aircraft

Abstract

The pitot tube and other components on the fuselage of the large civil aircraft generate significant aerodynamic noise during transonic cruise. In this paper, the Delayed Detached Eddy Simulation method is employed to simulate the flow field of a pitot tube model mounted on the wall composed by a pitot probe and a pitot tube strut at cruising Mach numbers. The far-field noise spectrum and directivity are obtained using the Ffowcs Williams-Hawkings’s integral. The results indicate that when the incoming Mach number is 0.85, the shock wave-boundary layer interaction is the primary noise source, with a frequency of approximately 600 Hz, acting as a dipole sound source. The total sound pressure level at a distance of 5 meters in the far field can reach 100 dB. Additionally, the pressure fluctuations of the probe head generate noise with a frequency exceeding 1000 Hz, which increases the total sound pressure level both upstream and downstream by 3 to 5 dB. When the Mach number of the incoming flow is 0.80, the pressure fluctuations at the probe becomes the main noise source, resulting in a total sound pressure level of 80 dB at both the upstream and lateral positions 5 meters away.