Numerical investigation of the flow inside a precession driven cylindrical cavity with additional baffles using an Immersed Boundary Method

In this paper we present a numerical approach to
solve the Navier-Stokes equations for arbitrary vessel geometries by
combining a Fourier-Spectral method with a direct forcing
Immersed Boundary method which allows to consider solid-fluid
interactions.
The approach is applied to a paradigmatic setup motivated by the precession dynamo experiment currently
under construction at Helmholtz-
Zentrum Dresden-Rossendorf (\textit{HZDR}). The experiment
consists of a fluid filled cylinder rotating about 2 axes which
induces a precession driven flow inside the cavity. The cylinder is
also equipped with baffles at the end caps with adjustable penetration depth
to impact the flow. The numerical details as well as simulation
results for the spin-up and precession driven flow in a circular cylinder
with additional baffles are presented.
The results provide a first confirmation that the use of such
baffles in the precession dynamo experiment is a useful way of influencing the flow,
allowing more efficient driving without changing the known flow
structure too much.