Effect of longitudinal lift distribution on sonic boom of a canard-wing-stabilator-body configuration

After the last flight of the Concorde in 2003,sonic boom has been one of the obstacles to the return of a supersonic transport aircraft to service.To reduce the sonic boom intensity to an acceptable level,it is of great significance to study the effect of lift distribution on far-field sonic boom,since lift is one of the most important contributors to an intense sonic boom.Existing studies on the longitudinal lift distribution used low-fidelity methods,such as Whitham theory,and in turn,only preliminary conclusions were obtained,such as that extending the lift distribution can reduce sonic boom.This paper uses a newly developed high-fidelity prediction method to quantitatively study the effect of longitudinal lift distribution on the sonic boom of a Canard-Wing-Stabilator-Body(CWSB)configuration.This high-fidelity prediction method combines near-feld CFD simulation with far-field propagation by solving the augmented Burgers equation.A multipole analysis method is employed for the extraction of near-field waveform in order to reduce computational cost.Seven configurations with the same total lift but different distributions are studied,and the quantitative relationship between the longitudinal lift distribution and far-field sonic boom intensity is investigated.It is observed that a small lift generated by the stabilator can prevent aft-stabilator and aft-fuselage shocks from merging,while the balanced lift generated by the canard and wing can effectively keep the corresponding shocks further apart,which is beneficial for reducing both the on-track and off-track sonic boom.In turn,the acoustic level perceived at the ground can be reduced by 5.9 PLdB on-track and 5.4 PLdB off-track,on average.