An FW-H Based Prediction Model for the Landing Gear Wake-Flap Interaction Noise

Abstract

A semi-empirical prediction model for landing gear wake-flap interaction noise is proposed in this paper. The prediction model is based on the time-domain Ffowcs Williams and Hawkings (FW-H) equations. The model is developed to predict the increase of noise due to the installation of a landing gear under a wing with deployed high-lift devices. The model uses FW-H samples collected during numerical simulations of an isolated landing gear and an isolated high-lift wing. To validate this model, the rod-airfoil benchmark case is tested in this paper. A Lattice Boltzmann Method (LBM) solver LaBS is used for the Computational Fluid Dynamics (CFD) simulations. The isolated rod simulation was performed to generate the necessary databases for the prediction model. The rod airfoil benchmark was simulated to validate the model’s prediction against the LBM/FW-H results. It was found the model yielded similar predictions as the simulation, and both compare excellently to experimental data. The ability of the model to predict the effect of the airfoil’s angle of attack and the gap between the rod and airfoil was investigated. The prediction model was found to predict spectra very similar to the LBM/FW-H methodology. The method does not require the interaction to be explicitly modelled and only uses isolated component simulations as an input. Therefore, the computational costs are much lower than if the turbulent wake and its impingement on the wing has to be explicitly modelled. The model has the potential to be a useful design tool to analyse landing gear/high-lift wing interaction noise.