## 1 Introduction  
The simulation of in-flight structural vibrations of an aeronautical vehicle requires modeling pressure fluctuations on its bounding surface and modeling the vehicle. The first diagram in Figure 1 represents the target simulation process. In-flight experiments are rare, and the ability of the simulation process to reproduce the measured dynamic behavior depends on:  
* the Computational Fluid Dynamics (CFD) simulation of the flow around the vehicle,
* the pressure fluctuation dimensionless model, and
* the vehicle vibroacoustic model. These three steps must be validated separately. The CFD simulation and the Turbulent Boundary Layer (TBL) pressure-fluctuation models are usually validated using wind tunnel experiments. The development of pressure-fluctuation models started in the 1960s with, in particular, works by [PERSON] [1] and [PERSON] [2]. Many improvements have been proposed since then. For subsonic flows without a pressure gradient, [PERSON]'s model has proven to be one of the most relevant models to date, fitting with several wind tunnel experiments [3]. Dedicated experiments have also focused on high Mach numbers for the modeling of ballistic vehicles. [PERSON] [4] and [PERSON] [5] proposed the first models in the 1960s; [PERSON] and [PERSON] [6] proposed improvements in the 1980s; and, more recently, these models have been challenged by new experiments (see [7,8] for example). These models have all been validated using wind tunnel experiments, which is the second process shown in Figure 1. The alternate validation process is the direct measurement of in-flight pressure fluctuations. Such data during hypersonic flight have been measured during the HI-FIRE experiment [9]. However, this type of measurement is extremely rare. Once the pressure-fluctuation model was chosen and the turbulent boundary layer simulated using dedicated CFD simulation, the surface dynamic load was defined in terms of the Power Spectral Density (PSD) level and surface correlation laws as a function of frequency. The response of a vibroacoustic model to this input can be computed. The full-frequency modeling of the vehicle must then be performed. In the low-frequency range, the most widely used modeling methods are based on the Finite Element Method (FEM). Once the vehicle has been modeled using structural finite elements, applying a distributed random dynamic pressure--which is correlated in space and frequency--is not trivial. A few articles have tackled this issue. Among them, [PERSON] and [PERSON] proposed an equivalent uncorrelated random pressure field [10], and [PERSON] et al. investigated several approaches to perform the computation efficiently [11]. The most widely used method for applying an acoustic loading to a structural finite element model is the modeling of the air volume surrounding the structure using the Boundary Element Method (BEM). Many examples may be found for automotive or aeronautical applications (see for example [12; 13; 14]). The combination with turbulent boundary layer pressure fluctuation loading has been studied, in particular, by [PERSON] for an aeronautical application [15] and by [PERSON] et al. with several correlation models applied on a plate [16]. At higher frequencies, the relevance of a finite element model decreases as the size of the elements cannot be considered small in comparison to the wavelengths of the vibration modes. Statistical Energy Analysis (SEA) [17] enables the prediction of high-frequency averaged vibration responses with a low computational cost. The response of an SEA model to turbulent boundary layer noise is often computed for the prediction of internal aircraft noise. For example, a recent SEA modeling of an aircraft fuselage was developed in [18]. Combining a Finite Element model and a SEA model may result in a full-frequency model of the structure. However, between high and low-frequency ranges, there may be a range where neither finite elements nor SEA are relevant. Many \"mid-frequency\" methods have been proposed to bridge this gap.