Comparison of Wind Tunnel Test Results of Suborbital Spaceplane FuJin with CFD Analysis

Computational Fluid Dynamics (CFD) analysis and wind tunnel testing had been conducted to evaluate the aerodynamic characteristics of the suborbital spaceplane FuJin (Model X-5), under development by the Tokyo University of Science (TUS) and the university start-up SPACE WALKER Inc. The FuJin conducts scientific missions at the altitude of up to 120 km. With a 100 kg payload, FuJin lifts off vertically and lands horizontally on a runway by the autonomous navigation, guidance and control (NGC) system. CFD analysis was performed by TUS along the optimized flight trajectory to develop of the aerodynamic database for the NGC design. The aerodynamic characteristics were evaluated in the clean configuration in terms of angle-of-attack, and in the aerodynamic control surface deflection configurations of elevator deflections (symmetric elevon deflections), aileron deflections (asymmetric elevon deflections), body-flap deflections and rudder deflections. Lower subsonic wind tunnel tests were carried out at the Institute of Space and Astronautical Science (ISAS) of JAXA in Japan, and lower supersonic to hypersonic wind tunnel tests were conducted at the Institute for Aerodynamics and Flow Technology of DLR in Germany. The CFD analysis was in good agreement with the wind tunnel test results. This paper demonstrates that CFD is an effective design tool to determine the aerodynamic characteristics of suborbital spaceplanes in all flight regimes.