A New Method for Fully Resolved Simulations of Fracturing in Fluid-Structure Interaction Problems

Fluid-Structure Interaction (FSI) is a complex, nonlinear, and multi-physics matter involving at the same time both fluid and solid mechanics. These are, in general, fully coupled problems where deformable solid media interact with fluid flow through a time-evolving interface

Scale-Resolving Simulation of Aeroacoustic Sound from Coanda Flaps

Deutsche Forschungsgemeinschaf

Modeling the pore level fluid flow in porous media using the immersed boundary method

This chapter demonstrates the potential of the immersed boundary method for the direct numerical simulation of the flow through porous media. A 2D compact finite differences method was employed to solve the unsteady incompressible Navier-Stokes equations with fourth-order Runge-Kutta temporal discretization and fourth-order compact schemes for spatial discretization. The solutions were obtained in a Cartesian grid, with all the associated advantages. The porous media is made of equal size square cylinders in a staggered arrangement and is bounded by solid walls. The transverse and longitudinal distances between cylinders are equal to two cylinder diameters and at the inlet a fully developed velocity profile is specified. The Reynolds number based on the cylinder diameter and maximum inlet velocity ranges from 40 to 80. The different flow regimes are identified and characterised, along with the prediction of the Reynolds number at which transition from steady to unsteady flow takes place. Additionally, the average drag and lift coefficients are presented as a function of the Reynolds number

Accurate estimate of drag forces using particle-resolved direct numerical simulations

An accurate force estimate for finite-size particle simulations is proposed based on Lagrange extrapolation of third order, coupled with a Taylor interpolation of the same order, to estimate pressure and viscous constraints on the surface of particles. The main point of our approach is to upwind the interpolation support in the normal direction to the fluid/solid interface so as to use only fluid values to estimate forces. Also, detailed validations of forces are considered for estimating accuracy and convergence order of the method on various incompressible motions such as the flow around an isolated particle at various Reynolds numbers and flows across packed spheres under faced-centered cubic, random, and bidisperse arrangements