2017 Volume 12 Issue 3 Pages JFST0026
A conceptual study of a supersonic cruise aircraft employing an airframe-integrated linear aerospike propulsion system was conducted based on the evaluation of the thrust performance, propulsion efficiency, cruise performance, and flight attitude characteristics. The thrust performance was evaluated through physics-based performance prediction models established for linear aerospike nozzles by accounting for the freestream effect based on wind tunnel experiments. The airframe geometry was premised to be similar to that of the Concorde but was given only a minor alternation in the span geometry and on-design flight conditions. The airframe configuration, equipped with a boattail integrated upstream of the primary cell nozzle exit of the primary airbreathing engine, enabled the freestream effect to be utilized by increasing the surface pressure of the linear aerospike-type airframe aft-body, thus increasing the total thrust. The boattail configuration is beneficial as it prevents potential thrust loss that is anticipated for transonic flight conditions. The force balance analysis indicated that the proposed conceptual aircraft is feasible in terms of the aerodynamic center location. Results of the feasibility study showed that both the cruise performance and fuel consumption efficiency can be improved by employing the airframe-integrated aerospike propulsion system compared with those of some existing supersonic aircraft. Thus, the minor alternation in airframe design based on the existing supersonic aircraft offers significant improvement in performance and environmental concerns.
