Direct aeroacoutic simulation of a ducted axial fan with acoustic liners using a volume penalization lattice Boltzmann solver on heterogeneous massively parallel platforms

Aeroacoustic noise of an axial fan is directly solved to understand its mechanism, using our in-house Lattice Boltzmann Method (LBM) solver. To make the LBM solver industrially successful, we must reduce calculation time while maintaining its accuracy. We adopt Volume Penalization method for moving boundaries to achieve independent parallelism, and to utilize GPU (Graphical Processing Units) for parallel computation. In this study, we present a comparison between numerical and experimental results of an axial fan in a lined duct. The acoustic liner is designed to reduce 2nd BPF noise, and the noise reduction of 9.8dB is observed in the experiment. With our LBM code, the noise reduction was reproduced within an accuracy of 2.5dB, and profound insights are provided through the detailed investigation of the numerical results.