Some Details of the Project
- Analysis Codes
- Currently, the analysis codes TACO
and TWAFER , developed
at Sandia National Laboratories, have been used to simulate the
thermal properties of CVD reactors.
- Interface Between Analysis Codes and Optimization Codes
- In an optimization framework, most analysis codes, including TACO
and TWAFER , can be used to evaluate objective functions and
constraints, but they usually do not provide design sensitivities,
essential for derivative based optimization methods. The automatic
differentiation tool ADIFOR,
developed at Argonne National Laboratories and Rice University,
generates derivative code that provides design sensitivities from
given analysis codes. While approximate derivatives can also be
computed from function values via finite differences, ADIFOR generates
`exact' derivatives in significantly less computing time. This leads
to better designs and faster design cycles.
- Optimization Codes
- The optimization packages TRICE,
developed at Rice University, and OPT++ developed at Sandia National
Laboratories, are used. Currently, OPT++ primarily includes codes for
nonlinear equations, unconstrained optimization and optimization with
simple bound constraints. TRICE is an optimization package designed
for nonlinear programming problems arising in optimal control and
engineering design problems. (It is planned to include the TRICE
algorithms into the OPT++ package.)