A Mixed-Fidelity Approach for Design of Low-Boom Supersonic Aircraft *

This paper documents a mixed-fidelity approach for the design of low-boom supersonic aircraft as a viable approach for designing a pract ical low-boom supersonic configuration. A low-boom configuration that is based on low-fidelit y analysis is used as the baseline. Tail lift is included to help tailor the aft portion of the g round signature. A comparison of low- and high-fidelity analysis results demonstrates the nec essity of using computational fluid dynamics (CFD) analysis in a low-boom supersonic configuration design process. The fuselage shape is modified iteratively to obtain a configuration with a CFD equivalent-area distribution that matches a predetermined low-boom target distribution. The mixed-fidelity approach can easily refine the low-fidelity low-boo m baseline into a low-boom configuration with the use of CFD equivalent-area analysis. The g round signature of the final configuration is calculated by using a state-of-the -art CFD-based boom analysis method that generates accurate midfield pressure distributions for propagation to the ground with ray tracing. The ground signature that is propagated from a midfield pressure distribution has a shaped ramp front, which is similar to the ground s ignature that is propagated from the CFD equivalent-area distribution. This result confi rms the validity of the low-boom supersonic configuration design by matching a low-boom equivalent-area target, which is easier to accomplish than matching a low-boom midfield pressure target.