TY - JOUR
T1 - A Normal Mode Stability Analysis of Numerical Interface Conditions for Fluid/Structure Interaction
AU - J. W. Banks & B. Sjögreen
JO - Communications in Computational Physics
VL - 2
SP - 279
EP - 304
PY - 2011
DA - 2011/10
SN - 10
DO - http://doi.org/10.4208/cicp.060210.300910a
UR - https://global-sci.org/intro/article_detail/cicp/7443.html
KW - 
AB - <p style="text-align: justify;">In multi-physics computations where a compressible fluid is coupled with
a linearly elastic solid, it is standard to enforce continuity of the normal velocities and
of the normal stresses at the interface between the fluid and the solid. In a numerical
scheme, there are many ways that velocity- and stress-continuity can be enforced in
the discrete approximation. This paper performs a normal mode stability analysis of
the linearized problem to investigate the stability of different numerical interface conditions
for a model problem approximated by upwind type finite difference schemes.
The analysis shows that depending on the ratio of densities between the solid and
the fluid, some numerical interface conditions are stable up to the maximal CFL-limit,
while other numerical interface conditions suffer from a severe reduction of the stable
CFL-limit. The paper also presents a new interface condition, obtained as a simplified
characteristic boundary condition, that is proved to not suffer from any reduction of
the stable CFL-limit. Numerical experiments in one space dimension show that the
new interface condition is stable also for computations with the non-linear Euler equations
of compressible fluid flow coupled with a linearly elastic solid.</p>