Trajectory optimization for maximizing cruise range of air-breathing hypersonic missile

The trajectory of an air-breathing hypersonic missile with slender body and thin airfoil is optimized. The missile is powered by a rocket based combined cycle (RBCC) system which combines modes of rocket and ramjet. The design objective is to maximize the cruise range for a given amount of fuel consumption. The design variables are parameterized by using non-uniform rational B-spline (NURBS). Consequently, the original optimal control problem is converted into an equivalent nonlinear parameter optimization problem which is then solved by using genetic algorithm. Results for three different cruise speeds, i.e. 5, 6 and 7 Ma, are obtained and compared. The results show that, for fuel economy, the cruise speed of the missile should not be too high. For the missile considered, under the condition of the same amount of fuel consumption, the alternative with the cruise speed of 5 Ma is able to attain the longest range.