Interdisciplinary modeling using computational fluid dynamics and control theory

For the modeling of high speed propulsion systems, there are at least two major categories of models, with several subdivisions in each category. One major category is characterized by computational fluid dynamics (CFD) and is highly accurate. CFD models can have millions of states, give a very complete view of the internal flow field, and run much slower than real-time on most computers. The other major category of models is used by control engineers for design and analysis of control systems. These models typically have on the order of ten to one hundred states, run near real-time, and capture the fundamental dynamics required for controller design. To provide improved control models particularly for these high speed systems, methods are needed that use the CFD techniques but yield models that are appropriate for both control analysis and design. The goal of this paper is to present/discuss some of the tools being developed to create an interdisciplinary technology bridge between the CFD and control disciplines.