Optimization and Computational Fluid Dynamics - Department of ...

8 Multi-objective Optimization in Convective Heat Transfer 235
P3 P4
2 a
P1 P2
W
Fig. 8.6 Geometric parametrization for the CC module using Catia
Bézier curves, which give the shape of both extruded virtual profiles forming
the flow channel. The half-height of the channel is controlled by parameter
a, while its width is defined by parameter W. The corrugation angle between
upper and lower plates is given by θ. By changing the parameter values,
various different geometries can be easily produced.
The geometry generated for a set of the parameters can be exported and
subsequently loaded by the software ANSYS ICEM-CFD [2], which generates
the grid. In this work, because of their superior accuracy for Finite Volume
discretization, only structured hexahedral grids have been used, but alternative
possibilities exist for more complicated geometries. The generated grid
is imported into the pre-processor cfx5pre of ANSYS CFX [1] where fluid
characteristics and boundary conditions are automatically defined. The case
file exported by the cfx5pre module is processed by the cfx5solve that solves
fluid and thermal equations. Finally the results are post-processed by the
cfx5post code to obtain the non-dimensional synthetic data for performance
evaluation.
8.6 Optimization Methods
In design, construction, and maintenance of any engineering system, technological
and managerial decisions have to be taken at several stages. The
objective of such a decision process is either to maximize the desired benefit
or to minimize the required effort in terms of time, money, materials, energy,
environmental impact, etc. Such a process can be abstracted from the engineering
field and applied to whatsoever situation in which human choice is
present.
A decision-making environment can be linked to the concept of system.
A system is an entity, a set of logical or physical connections that gives