2020/04/30 by Thomas Astoul, Astoul, Thomas, Gauthier Wissocq +7
Engineering · #Lattice Boltzmann Simulation Studies #Aerosol Filtration and Electrostatic Precipitation #Aerodynamics and Acoustics in Jet Flows
paper · pdf · doi:10.48550/arxiv.2004.14887
The present study proposes a highly accurate lattice Boltzmann direct\ncoupling cell-vertex algorithm, well suited for industrial purposes, making it\nhighly valuable for aeroacoustic applications. It is indeed known that the\nconvection of vortical structures across a grid refinement interface, where\ncell size is abruptly doubled, is likely to generate spurious noise that may\ncorrupt the solution over the whole computational domain. This issue becomes\ncritical in the case of aeroacoustic simulations, where accurate pressure\nestimations are of paramount importance. Consequently, any interfering noise\nthat may pollute the acoustic predictions must be reduced.\n The proposed grid refinement algorithm differs from conventionally used ones,\nin which an overlapping mesh layer is considered. Instead, it provides a direct\nconnection allowing a tighter link between fine and coarse grids, especially\nwith the use of a coherent equilibrium function shared by both grids. Moreover,\nthe direct coupling makes the algorithm more local and prevents the duplication\nof points, which might be detrimental for massive parallelization. This work\nfollows our first study (Astoul~\et al. 2020) on the deleterious effect\nof non-hydrodynamic modes crossing mesh transitions, which can be addressed\nusing an appropriate collision model. The Hybrid Recursive Regularized model is\nthen used for this study. The grid coupling algorithm is assessed and compared\nto a widely-used cell-vertex algorithm on an acoustic pulse test case, a\nconvected vortex and a turbulent circular cylinder wake flow at high Reynolds\nnumber.\n