Inverse Design of Low-Boom Supersonic Concepts Using Reversed Equivalent-Area Targets

摘要

A promising path for developing a low-boom configuration is a multifidelity approach that starts from a low-fidelity low-boom design, refines the low-fidelity design with computational fluid dynamics equivalent-area analysis, and improves the design with sonic-boom analysis by using computational fluid dynamics off-body pressure distributions. The focus of this paper is on the third step of this approach, in which the design is improved with sonic-boom analysis through the use of computational fluid dynamics calculations. A new inverse design process for off-body pressure tailoring is formulated and demonstrated with a low-boom supersonic configuration that was developed by using the mixed-fidelity design method with computational fluid dynamics equivalent-area analysis. The new inverse design process uses the reverse propagation of the pressure distribution from a mid-field location to a near-field location, converts the near-field into an equivalent-area distribution, generates a low-boom target for the reversed equivalent area of the configuration, and modifies the configuration to minimize the differences between the configuration's reversed equivalent area and the low-boom target The new inverse design process is used to modify a supersonic demonstrator concept for a cruise Mach number of 1.6 and a cruise weight of 30,000 lb. The modified configuration has a fully shaped ground signature that has a perceived loudness value of 78.5, whereas the original configuration has a partially shaped aft signature with a perceived loudness of 82.3.