Numerical study of inlet distortion under crosswind conditions using OpenFOAM

The objective of this study is to evaluate the inlet distortion occurring at the nacelle inlet under crosswind conditions and to predict the hysteresis of boundary layer separation in the nacelle inlet. To achieve this, we conducted numerical simulations of the fan rotation test measured by Hosono et al. (2022) using OpenFOAM. The hysteresis of separation was successfully predicted qualitatively using unsteady simulations by varying the nacelle back pressure over time. The capability of prediction was further improved by considering the roughness of the nacelle wall. The results confirmed that the laminar boundary layer separates around the nacelle lip, followed by a laminar/turbulent boundary layer transition. However, the distortion strength was generally overestimated compared to the experimental data.