A Rapid Design Method for Quiet Spike of Supersonic Transport Aircraft

The severe sonic boom remains a great challenge for the return of supersonic transport aircraft to market. Among the sonic boom reduction methods, quiet spike technology is still one of the most effective ways during the last two decades. The quiet spike design studies were carried out by combining the near-field computational fluid dynamics (CFD) simulation with the far-field waveform parameter method. However, employing the expensive CFD method to obtain a near-field waveform is very time-consuming for a complex supersonic aircraft. Meanwhile, a low-fidelity waveform parameter method could not predict rise time. This paper proposes a rapid method for the design of a quiet spike, with the goal of reducing sonic boom intensity for a conceptual design stage. The design optimization method is used in the shape design of a spike-mounted configuration. For sonic boom prediction, the modified linear theory is utilized to partially replace the time-consuming CFD method to rapidly obtain near-field waveform, and then the augmented Burgers equation is solved for predicting the far-field signature. Validations of the modified linear theory for sonic boom prediction and CFD simulation are performed by using a NASA cone and a delta-wing-body configuration, respectively. The far-field sonic boom prediction method is validated by comparison with flight test data of an F-5E aircraft. The proposed method is then applied to design the quiet spike for a supersonic aircraft. Results show that the ground on-track sonic boom intensity can be reduced by 3.3 PLdB, compared with that of the baseline configuration.