Towards Wall-Modeled LES with Lattice Boltzmann Method for Aeroacoustics: Application and Understanding

Abstract

The aim of this work is direct noise computation (DNC) of high-lift wing using Wall-modeled LES (WMLES) with Lattice Boltzmann Method (LBM). There are two aspects of this work: application, where the commercial LB solver ProLB is used as a DNC tool to compute highlift noise, and understanding, where an effort is made to gather know-how about the intricate details/nuances involved with wall-modeling in LBM by implementing it. For the present study, the Category 6 LEISA2 F16 high-lift configuration from the Benchmark for Airframe Noise Computations (BANC) workshop has been selected as the high-lift airfoil. The three-element unswept high-lift wing with deployed slat and flap is resolved on a mesh with different spanwise resolutions ranging from 5% to 20% clean chord length. Periodic boundary condition is used along the spanwise direction. The results of WMLES-LBM simulations were validated for relative accuracy against the extensive experimental BANC database. Results of both aerodynamic and aeroacoustic comparison with the experiments is discussed in detail. For the aspect of understanding, a quasi-analytical wall function for flat walls has been introduced into the academic LB research code Musubi. Results of the simulation were compared with the published DNS results.