机翼表面脉动压力的空间和频域特性数值研究

The wing surface pressure fluctuation is one of the main sources of large passenger aircraft near-field noise, and the study of its spatial and frequency domain distribution characteristics is of great significance. The large eddy simulation method were used to carry out Re_C = 2.42×10⁶ numerical calculation research for an infinite wingspan NLF(2)-0415 airfoil with a chord length of 1 m and a sweep angle of 45 degrees. The effects of different turbulent incoming flow conditions and flow states on the time-averaged flow field and pressure fluctuation sound pressure level and power spectrum on the upper surface of the wing were analyzed. The research results show that under the conditions of this paper, the pressure fluctuation on the upper surface of the wing has an obvious sudden increase at the transition position; the sound pressure level in the turbulent flow zone is about 20～30 dB higher than that in the laminar flow zone; the influence of the incoming turbulence intensity on the surface pressure fluctuation is mainly concentrated in the laminar flow zone, and the pressure fluctuation in the turbulent zone is not sensitive to the incoming turbulence intensity; the pressure fluctuation power spectrum in the laminar flow zone is generally low, and decreases fast as the frequency increases; the pressure fluctuation power spectrum in the turbulent flow zone is increased by about 2～3 orders of magnitude in the whole frequency band compared with the laminar flow zone, and the spectrum level changes little with frequency in the low frequency range, and decreases with a certain slope as the frequency increases in the high frequency range.