title: Hybrid lattice Boltzmann method on overlapping grids.
abstract: In this work, a hybrid lattice Boltzmann method (HLBM) is proposed, where the standard lattice Boltzmann implementation based on the Bhatnagar-Gross-Krook (LBGK) approximation is combined together with an unstructured finite-volume lattice Boltzmann model. The method is constructed on an overlapping grid system, which allows the coexistence of a uniform lattice nodes spacing and a coordinate-free lattice structure. The natural adaptivity of the hybrid grid system makes the method particularly suitable to handle problems involving complex geometries. Moreover, the provided scheme ensures a high-accuracy solution near walls, given the capability of the unstructured submodel of achieving the desired level of refinement in a very flexible way. For these reasons, the HLBM represents a prospective tool for solving multiscale problems. The proposed method is here applied to the benchmark problem of a two-dimensional flow past a circular cylinder for a wide range of Reynolds numbers and its numerical performances are measured and compared with the standard LBGK ones.
authors.affiliation: University of Naples "Parthenope," Centro Direzionale Isola C4, 80133 Naples, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Di Ilio
authors.affiliation: University of Rome "Niccolò Cusano," Via don Carlo Gnocchi 3, 00166 Rome, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Chiappini
authors.affiliation: University of Tuscia, Largo dell'Università snc, 01100, Viterbo, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Ubertini
authors.affiliation: University of Rome "Tor Vergata," Via del Politecnico 1, 00133 Rome, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Bella
authors.affiliation: Istituto Applicazioni Calcolo, CNR, Via dei Taurini 19, 00185 Rome, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Succi