A Cartesian Method with Second-Order Pressure Resolution for Incompressible Flows with Large Density Ratios

Michel Bergmann (1) , Lisl Weynans (2)

1 MEMPHIS - Modeling Enablers for Multi-PHysics and InteractionS
2 CARMEN - Modélisation et calculs pour l'électrophysiologie cardiaque

An Eulerian method to numerically solve incompressible bifluid problems with high density ratio is presented. This method can be considered as an improvement of the Ghost Fluid method, with the specificity of a sharp second-order numerical scheme for the spatial resolution of the discontinuous elliptic problem for the pressure. The Navier–Stokes equations are integrated in time with a fractional step method based on the Chorin scheme and discretized in space on a Cartesian mesh. The bifluid interface is implicitly represented using a level-set function. The advantage of this method is its simplicity to implement in a standard monofluid Navier–Stokes solver while being more accurate and conservative than other simple classical bifluid methods. The numerical tests highlight the improvements obtained with this sharp method compared to the reference standard first-order methods.

Mots clés: immersed interfaces; level-set; interface unknowns; Cartesian grid; finite differences; projection method; incompressible Navier-Stokes equations

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

Michel Bergmann, Lisl Weynans. A Cartesian Method with Second-Order Pressure Resolution for Incompressible Flows with Large Density Ratios. Fluids, 2021, 6 (11), pp.402. ⟨10.3390/fluids6110402⟩. ⟨hal-03506971⟩