Natural laminar flow wing for supersonic conditions: Wind tunnel experiments, flight test and stability computations

In the framework of next supersonic transport airplane generation, the Japan Aerospace eXploration Agency (JAXA) has developed a new natural laminar flow highly swept wing. The design has been experimentally validated firstly in a supersonic wind tunnel and secondly accomplishing flight test. These experimental data were then analyzed and completed by numerical stability analyses in a joint research program between Onera and JAXA. At the design condition, for a Mach number M=2 at an altitude of h=18 km, results have confirmed the laminar design of the wing due to a strong attenuation of cross-flow instabilities ensuring an extended laminar zone. As the amplification of disturbances inside the boundary layer and transition process is very sensitive to external parameters, the impact of wall roughness of the models and the influence of Reynolds number on transition process have been carefully analyzed.