## 1 Introduction
[8] combined the Spalart-Allmaras detached eddy simulation (DES) method with a statistical energy analysis (SEA) model to investigate the relative contribution of the convective and acoustic pressure fluctuations around a car side window to the interior of a full-sized DrivAer clay model. They revealed that the contribution of the acoustic fraction was more dominant than the convective one. However, the DES model uses the RANS solver in the boundary layer flow, which captures only the coherent structure related to the tonal aerodynamic noise source. Furthermore, the SEA model was used as a vibroacoustic solver, for which the validity is limited in the middle- and high-frequency range and only in terms of the averaged band spectrum. The reliable vibroacoustic solver and computational aeroacoustic methods are critical for the accurate prediction of interior wind noise of a land vehicle. In this respect, some studies paid close attention to figuring out the transfer characteristics of the wall pressure fluctuations to an interior cabin through the front side glass of the vehicle. [PERSON] et al. [9] developed an analytical solution for the sound transmitted into a rigid rectangular cavity by a flexible plate excited by the turbulent boundary layer of an external grazing flow. The averaged sound power was calculated to estimate the contribution of the compressible and incompressible pressure components to the flow-induced noise inside the cavity. However, this study was limited to the problem of simple geometry. [PERSON] et al. [10] studied the transmission characteristics and mechanism of the exterior wall pressure fluctuation on the side window of a full-size DrivAer model to the interior wind noise by using a simplified rectangular window-cabin equivalent model. They investigated the fundamental cause of different transmission efficiency between two pressure components. Although the analytic model provided a clear theoretical interpretation of different transmission characteristics between the compressible and incompressible pressure fields, it is difficult to extend the model to practical problems involving complex geometries for which analytic models are generally not available. The structural components of high-speed vehicles are inevitably subject to and, thus, excited by external surface pressure fields within turbulent boundary layers due to the external flow disturbances induced by their motions [11, 12, 13, 14, 15]. From a fluid-structure interaction (FSI) perspective, the accurate computation of structural vibration induced by turbulent boundary layers is still a very challenging problem. The input power for the structural vibration must consider not only the random excitation force but also the vibrational characteristics of the structure itself [16, 17]. Although the injected power formula is applied through various assumptions, most input power formulas do not reflect the vibration characteristics of the structure [18, 19, 20]. In this study, a reliable, systematic numerical methodology is proposed for the accurate and efficient prediction of the interior noise of a high-speed vehicle due to external flow disturbances. The developed numerical methods consist of three sequential methods suitable to each physical step causing the indoor transmission of external compressible and incompressible surface pressure fields. In the first step, the large eddy simulation (LES) technique with high-resolution grids is used to accurately compute external aerodynamic and aeroacoustic fields around a vehicle. In the second step, the wavenumber-frequency transform is used to decompose the surface pressure fluctuations on the windows of a vehicle into incompressible and compressible ones. The separation is based on the physical fact that the phase speeds of incompressible and compressible pressure waves differ. Lastly, the interior sound pressure levels are predicted using the vibroacoustic model based on the coupled finite element (FE) and SEA methods with the input of each incompressible and compressible pressure field.