Development and validation of Navier–Stokes characteristic boundary conditions applied to turbomachinery simulations using the lattice Boltzmann method

Thomas Gianoli (1, 2, 3) , Jean‐françois Boussuge (2) , Pierre Sagaut (1) , Jérôme de Laborderie (3)

1 M2P2 - Laboratoire de Mécanique, Modélisation et Procédés Propres
2 CERFACS - Centre Européen de Recherche et de Formation Avancée en Calcul Scientifique
3 Safran Aircraft Engines

This article reports a procedure to implement as well as to validate non-reflecting boundary conditions applied for turbomachinery simulations, using Navier-Stokes characteristic boundary conditions in a compressible lattice Boltzmann solver. The implementation of both an inlet condition imposing total pressure, total temperature, and flow angles, as well as an outlet condition imposing a static pressure profile that allows the simulation to reach a simplified radial equilibrium, is described within the context of a lattice Boltzmann approach. The treatment at the boundaries relies on the characteristic methodology to derive conditions which are non-reflecting in terms of acoustics and is also compatible with turbulence injection at the inlet. These properties are evaluated on test cases of increasing complexity, ranging from a simple 2D periodic domain to an S-duct stage with turbulence injection.

Mots clés: characteristic boundary conditions; lattice Boltzmann method; LODI; turbomachinery

Domaines: Mécanique des fluides [physics.class-ph]

Thomas Gianoli, Jean‐françois Boussuge, Pierre Sagaut, Jérôme de Laborderie. Development and validation of Navier–Stokes characteristic boundary conditions applied to turbomachinery simulations using the lattice Boltzmann method. International Journal for Numerical Methods in Fluids, 2023, 95 (4), pp.528-556. ⟨10.1002/fld.5160⟩. ⟨hal-04063964⟩