Optimization of Combined Rocket and Ramjet/Scramjet Ballistic Missile Designs

摘要

A preliminary design optimization of a revolutionary concept involving integrated airbreathing propulsive assist is presented. The conceptual design for the proposed airbreathing thrust augmenter is an annular ramjet/scramjet integrated into a liquid-oxygen-rocket propellant rocket core. The airbreathing engine makes use of the same tankage and turbopump hardware as the rocket engine for supplying fuel. The aeropropulsive environment is simulated using an axisymmetric Euler solver with a decoupled semiempirical viscous model. The flight performance is simulated using a seventh- to eight-order Runge-Kutta integrator for the six-degree-of-freedom dynamics. The optimizer used for design iterations is a binary-encoded genetic algorithm with a proven track record for addressing complex flight vehicle design problems. Results show the marked improvement in performance achieved by the use of such thrust augmenters on a military-dominated niche of the overall spectrum of missile designs.