Scramjet missile design using genetic algorithms

The objective of this effort was to show that scramjet powered vehicle designs which are optimized for a given flight condition can be found using predictive modeling tools and a genetic algorithm (GA). This required the assimilation of basic modeling tools for the external aerodynamics, the engine internal ballistics for thrust and additive drag predictions, and for the mass and inertia properties. The GA routines for optimizing the design have been used in other design optimization efforts. The basic models have been assembled and specific designs have been developed. Results indicate that the flight envelope for a scramjet is very narrow and dimensions are critical if the engine is to develop thrust at a given design point. For the designs considered in this investigation, specific Mach number and altitude limits were established and dimensional designs were identified. Utilization of these codes and representative results are documented in this paper.