Steady-State Aerodynamic Modeling Architecture Overview

Abstract

An aerodynamic model is a mathematical representation of the behavior of a vehicle in free flight, and the architecture defines the set of variables and equations used to construct the aerodynamic forces and moments. Aeromodels are widely used to represent aerodynamic performance during the design, development, and validation of air vehicles. Architecture selection drives source data requirements and therefore has ramifications for simulation accuracy, program cost, and schedule. This paper describes four approaches appropriate for simple cruciform airframes and provides selection rationale for each. These architectures employ table lookups and the principle of superposition to combine basic stability and control effectiveness components. Body axis mixed architecture provides an efficient method for modeling winged vehicles with limited maneuver requirements. Maneuver mixed-panel architecture enables efficient data collection for a wide range of airframe configurations, providing high accuracy around trim points. Single-panel architecture allows a large domain of flight conditions to be modeled with first-order accuracy using a relatively small data set. Lastly, polar architecture is ideal to reduce the number of independent variable dimensions for spinning projectiles. The architectures described are for the core of the aerodynamic model: steady-state aerodynamic behavior without detailed drag buildup, uncertainty, stability derivatives, transient effects, or application-specific elements.