Aerodynamic Shape Design of Hypersonic Booster with RBCC Engine for TSTO Vehicle

Abstract

An appropriate configuration of a hypersonic booster plane with the rocket-based-combined-cycle (RBCC) engine was studied for the two-stage-to-orbit (TSTO) reusable space transportation system. Assuming the flight path at a constant dynamic pressure followed by a constant acceleration G, the ascent trajectory and the vehicle sizing were numerically analyzed. The feasibility of the design was evaluated by the ratio of the vehicle mass after the orbiter separation to the takeoff mass. A rocket-propelled orbiter of 75 ton with the separation speed at 3000 m/s was considered as the upper stage. The results show that a vehicle with the takeoff mass smaller than 600 ton including the orbiter can be realized under the constraint of the maximum acceleration at 1 G. The reduction in the drag force to the level of C D =0.01 is strictly required for successful TSTO design. A vehicle with the RBCC engine can continue to accelerate by using the rocket mode in low atmospheric density environment, and has an advantage to conduct the orbiter separation at a high altitude, avoiding hazardous aerodynamic interference. From a hypersonic aerodynamic viewpoint, a waverider-derived vehicle with twin engines on the upper surface and the internal bay, in which the orbiter is placed and released backward, is recommended.