Aeroacoustic mechanisms and control of high-lift configuration via wall-modeled lattice Boltzmann method

The leading-edge slat in high-lift systems represents a dominant aeroacoustic source, driven by unsteady dynamics in the slat cove. Resolving turbulent structures on Cartesian grids presents a fundamental conflict between near-wall resolution and computational efficiency. To address this, we propose LBAcoustics, a framework based on the lattice Boltzmann method (LBM). It incorporates a near-wall modeling strategy that couples an interpolation bounce-back (IBB) scheme with wall function. This approach is validated against the 30P30N airfoil, effectively eliminating non-physical flow separation at an acceptable computational cost. The coupling of dynamic mode decomposition (DMD) and vortex sound theory facilitates the separation of hydrodynamic and acoustic fluctuations. Furthermore, the coherent superposition model reveals that large-scale coherent structures in the slat cove dominate noise generation because of their constructive interference, as validated by high magnitude-squared coherence. In addition, we establish a frequency-dependent physical map: low-frequency noise arises from global shear-layer flapping; mode fa stems from periodic vortex impingement at the reattachment point; fb is driven by two-/three-dimensional transition of Kelvin–Helmholtz (K–H) vortices; and fc results from trailing-edge scattering. Based on these insights, a steady-jet active flow control (AFC) strategy is implemented. The actuation creates a fluidic barrier that topologically restructures the shear layer, achieving a global noise reduction of 5.5 dB. Notably, the strategy virtual eliminates narrowband peaks (NBPs), with a maximum reduction peaking at 32 dB at fb.