Aerodynamic Design Criteria for Supersonic Climb-Cruise Missiles

Abstract

An analytical technique is presented which establishes the relationship between aerodynamic characteristics and total mission performance for ramjet-powered missiles which are launched at low altitude and must climb to high altitude for a long-range cruise at supersonic speeds. The analytical expressions obtained can be used to determine desirable aerodynamic characteristics and their variation with velocity given missile propulsion and design parameters such as specific fuel consumption, thrust coefficient, planform area, nozzle exit area, and weight. The expressions are derived for Rutowski minimum fuel-to-climb profiles and optimum specific fuel consumption cruise conditions. The low-altitude segment of the climb is shown to be dominated by the drag coefficient CD . and its variation with velocity. At high altitudes during the climb, the induced drag factor K becomes important. Therefore, reducing Q>min at low supersonic speeds and K at high supersonic speeds reduces fuel consumption during the climb. The desirable lift coefficient at minimum drag CL() is shown to be small at low speeds and to increase with velocity. The ideal climb-cruise configuration will have a Q>mjn and K which are low at low speeds and decrease strongly with increasing speed. The CL() will also be low at low speed but increase greatly with increasing speed. These results and the analytical expressions derived can be used by the missile designer as aerodynamic design criteria during configuration development.