Modeling Flight: The Role of Dynamically Scaled Free-Flight Models in Support of NASA's Aerospace Programs

The state of the art in aeronautical engineering has been continually accelerated by the development
of advanced analysis and design tools. Used in the early design stages for aircraft and spacecraft, these
methods have provided a fundamental understanding of physical phenomena and enabled designers to
predict and analyze critical characteristics of new vehicles, including the capability to control or modify
unsatisfactory behavior. For example, the relatively recent emergence and routine use of extremely power-
ful digital computer hardware and software has had a major impact on design capabilities and procedures.
Sophisticated new airlow measurement and visualization systems permit the analyst to conduct micro- and
macro-studies of properties within low ields on and off the surfaces of models in advanced wind tunnels.
Trade studies of the most eficient geometrical shapes for aircraft can be conducted with blazing speed
within a broad scope of integrated technical disciplines, and the use of sophisticated piloted simulators in
the vehicle development process permits the most important segment of operations—the human pilot—to
make early assessments of the acceptability of the vehicle for its intended mission. Knowledgeable applica-
tions of these tools of the trade dramatically reduce risk and redesign, and increase the marketability and
safety of new aerospace vehicles.