Automated Parameter Studies Using a Cartesian Method

A modular process for performing general parametric studies about an aerodynamic configuration using a Cartesian method is described. A novel part of this process is the automatic handling of general control surfaces deflections based upon simple, userspecified inputs. The article focuses on the use of aerodynamic databases in the design process. Database fly-through is used to develop and analyze guidance and control systems, and to evaluate performance data. Validation comparisons with experimental data and Navier-Stokes simulations are presented for the Langley Glide-Back Booster vehicle. Two example parametric databases with control surfaces deflections are presented: an autonomous Mars explorer aircraft which contains 4700 datapoints and two movable elevons, and the Space Shuttle launch vehicle in ascent configuration with gimbaling engine nozzles. The database for the Mars aircraft has been used to validate a generic neural-network control system, and trajectory simulations using the shuttle aerodynamic data are coupled with an optimization algorithm to develop a closed-loop feedback pitch controller.