Estimating Noise Induced by Turbulent Boundary Layers Using the Acoustic-Structural Reciprocity Technique*

As the contribution of self-noise from flow has increased in aerodynamic applications, there is growing interest in numerically predicting the noise generated by wall pressure fluctuations in turbulent boundary layers [1-3]. In this study, we explored a prediction method for flow-induced noise in an aircraft wing cavity, using a simplified aerodynamic model. To capture the temporal and spatial randomness of wall pressure fluctuations, we adapted a random vibro-acoustics approach. The structural excitation by wall pressure fluctuations was modeled using the Corcos model and the Smol'yakov-Tkachenko model [4]. The acoustic-structural reciprocity technique was applied to efficiently calculate the transfer functions required for the random vibroacoustic model. This technique enables the effective computation of noise transfer functions at multiple points, facilitating the application of the random vibro-acoustics method [5]. To verify the acoustic-structural reciprocity technique, we compared the transfer functions in both direct and reciprocal directions, finding good agreement. In addition, we studied the effects of flow velocity on noise levels in the cavity and observed that the noise level increases with increasing flow velocity. We developed a prediction method for noise generated by flow over a structure, which has potential applications in estimating aircraft self-noise.