Test
cases
The data for the
estimation of the discretization error/uncertainty of functional and local flow
quantities was obtained from six statistically steady, two-dimensional flows of
an incompressible fluid computed with the open-usage viscous flow code ReFRESCO
(www.refresco.org):
·
Flow over a flat plate at three
different Reynolds numbers based on the plate length, incoming velocity
and fluid kinematic viscosity
,
.
I.
.
II.
.
III.
.
·
Flow around a NACA 0012 airfoil at
Reynolds number based on the airfoil chord , incoming velocity
and fluid kinematic
viscosity
of
at three angles of
attack
:
IV.
.
V.
.
VI.
.
For these six cases, simulations were
performed with three isotropic eddy-viscosity turbulence models:
a.
The
one-equation model of Spalart & Allmaras in the formulation without the
tripping term (SAnoft2).
b.
The
Shear-Stress Transport (SST) k-w two-equation model.
Different cases available will be designated
according to the numbering presented above. For example, CASE IVb corresponds
to the flow around the NACA 0012 airfoil at simulated with the SST k-w two-equation model.
All calculations were performed using double
precision (15 digits) and iterative convergence criteria based on the maximum (norm) normalized residual
of all transport
equations solved for each flow condition. Normalized residuals are equivalent
to the change of dimensionless dependent variables in a simple Jacobi iteration.
Reference values are the fluid density
,
and
for the plate flow and
,
and
for the flow around
the airfoils. Maximum values of
for the six test cases
are given below.
Test Case |
Flat Plate |
NACA 0012 |
||||
I |
II |
III |
IV |
V |
VI |
|
|
10-8 |
10-8 |
5×10-8 |
10-8 |
2×10-8 |
2×10-8 |