Abstract (EN):
Accurate predictions of viscoelastic flows require
discretisation schemes for convection of at least
second-order accuracy. In an important paper,
Godunov [1] demonstrated that all monotone
(bounded) linear schemes could be at most firstorder accurate. The only way to avoid this
limitation is thus the development of nonlinear
composite schemes, usually referred to as highresolution schemes (HRS). Several discretisation
schemes were proposed in the last years based
on either the total variation diminishing framework
(TVD) [2], on the normalised variable formulation
(NVF) [3], or others. The NVF approach has been
extended to non-uniform grids yielding the
normalised variable and space formulation
(NVSF) [4], to be used here. Although HRS¿s have
seen widespread usage in the last years, there
are still some convergence difficulties with these
methods [5]. This work aims at developing a new
HRS with good accuracy and enhanced
convergence properties. The new scheme, named
Convergent and Universally Bounded
Interpolation Scheme for the Treatment of
Advection (CUBISTA), has similar accuracy to the
well-known SMART scheme [6], both being thirdorder accurate on uniform meshes.
The upper-convected Maxwell (UCM) model was
selected to assess the performance of the
CUBISTA scheme due to the hyperbolic nature
and the known numerical difficulties of these
stress equations. The benchmark flow of a UCM
fluid in a 4:1 planar contraction is used to
compare the performance of different highresolution schemes, and thus serving to illustrate
the superiority of the CUBISTA scheme in terms
of iterative convergence (robustness).
Language:
English
Type (Professor's evaluation):
Scientific
No. of pages:
4