Sweep Effects on Slat Tonal Noise

Wall-resolved large-eddy simulations (WRLES) are performed for the 30P30N high-lift configuration using a novel, self-developed high-order flux reconstruction (FR) solver. This study presents several key innovations, including the implementation of a computationally efficient setup that achieves fourth-order accuracy and successfully demonstrates the capability of FR-based WRLES for predicting slat noise. The numerical framework is validated against experimental datasets and prior numerical results. Notably, this work highlights two major contributions: 1) a remarkable computational efficiency with only 74 GPU hours required to simulate 10 flow pass times at a Reynolds number of 1.71 × 10⁶ and a 5.5 deg angle of attack, which establishes best practices for FR-based WRLES simulations, and 2) the sweep effects investigation examines sweep angles ranging from 20 to 40 deg, encompassing typical values in modern commercial aircraft designs. Key findings reveal a progressive weakening of the feedback mechanism as the sweep angle increases. Furthermore, the phase-coherence analysis identifies spanwise interference caused by spatial misalignment of acoustic feedback loops, which evolves into total destructive interference at the 40 deg sweep angle configuration. This phenomenon effectively suppresses tonal noise generated by the feedback mechanism. The cumulative effects of these mechanisms result in a 9.1 dB noise reduction for the 40 deg swept configuration.