- kEpsilonPhitF is a kEpsilon-based model which originated
from (Durbin, 1995)’s v2-f methodology. However, the majority of
v2-f model variants proved to be numerically stiff for segregated
solution algorithms due to the coupled formulations of v2 and f fields,
particularly on wall boundaries.
The v2-f variant (i.e. OpenFOAM’s v2f model) due to
(Lien and Kalitzin, 2001) reformulated the original v2-f model to enable
segregated computations; however, a number of shortcomings regarding
the model fidelity were reported in the literature.
To overcome the shortcomings of the v2-f methodology, the v2-f approach
was re-evaluated by (Laurence et al., 2005) by transforming v2 scale into
its equivalent non-dimensional form, i.e. phit, to reduce the numerical
stiffness.
This variant, i.e. kEpsilonPhitF, is believed to provide numerical
robustness, and insensitivity to grid anomalies while retaining the
theoretical model fidelity of the original v2-f model.
Accordingly the v2f RANS model is deprecated in favour of the variant
kEpsilonPhitF model.
When activeDesignVariables are not set explicitly, all design variables
are treated as active. These were allocated properly when starting from
0 but not when starting from an intermediate optimisation cycle
(e.g. running 5 optimisation cycles, stopping and restarting).
TUT: added a new tutorial including the restart of an optimisation run
to help identify future regression
The controlBoxes wordList was removed from NURBS3DVolume in the
pre-release phase but writeMorpherCPs was not updated accordingly.
TUT: added the invocation of writeMorpherCPs in one of the tutotials to
help identify future regression
- ensure that the updateControl is "non-sticky" on re-read,
even if we do not support runtime-modifiable here
STYLE: add syntax example (wingMotion), but with updateInterval 1
The adjoint library is enhanced with new functionality enabling
automated shape optimisation loops. A parameterisation scheme based on
volumetric B-Splines is introduced, the control points of which act as
the design variables in the optimisation loop [1, 2]. The control
points of the volumetric B-Splines boxes can be defined in either
Cartesian or cylindrical coordinates.
The entire loop (solution of the flow and adjoint equations, computation
of sensitivity derivatives, update of the design variables and mesh) is
run within adjointOptimisationFoam. A number of methods to update the
design variables are implemented, including popular Quasi-Newton methods
like BFGS and methods capable of handling constraints like loop using
the SQP or constraint projection.
The software was developed by PCOpt/NTUA and FOSS GP, with contributions from
Dr. Evangelos Papoutsis-Kiachagias,
Konstantinos Gkaragounis,
Professor Kyriakos Giannakoglou,
Andy Heather
[1] E.M. Papoutsis-Kiachagias, N. Magoulas, J. Mueller, C. Othmer,
K.C. Giannakoglou: 'Noise Reduction in Car Aerodynamics using a
Surrogate Objective Function and the Continuous Adjoint Method with
Wall Functions', Computers & Fluids, 122:223-232, 2015
[2] E. M. Papoutsis-Kiachagias, V. G. Asouti, K. C. Giannakoglou,
K. Gkagkas, S. Shimokawa, E. Itakura: ‘Multi-point aerodynamic shape
optimization of cars based on continuous adjoint’, Structural and
Multidisciplinary Optimization, 59(2):675–694, 2019
- use sed instead of foamDictionary and avoid log file
- ensure consistent behaviour with plot script
GIT: added missing 0/k field : inlet values still need adjustment
- an advanced feature, for example when sampling on a static patch
while some motion occurs elsewhere. [use with caution]
- If the sampled surface dictionary is modified during run-time, the
ensight file indexing for the geometry will become out of sync.
This is addressed in a subsequent commit.
