03.1 - Aerodynamics – CFD Methods and Validation
NUMERICAL PREDICTION OF FOCUS BOOM GENERATED BY MANEUVERS
S. Han¹, Y. Xu¹; ¹Chinese Aeronautical Establishment, China
The acceleration from subsonic to supersonic performed by supersonic civil aircraft generates focus boom on the ground. The intensity of focus boom is several times higher than that of the cruising sonic boom, which greatly exceeds the low boom requirements for the commercial flight of supersonic civil aircraft. A numerical prediction method for sonic boom focusing based on the Lossy Nonlinear Tricomi Equation was studied and computational aeroacoustics techniques were applied to reduce the dispersion and dissipation caused by numerical method. The corresponding focus boom prediction code CBoom_NLTE, was developed. The numerical verification of the developed code was performed using SCAMP flight data, which indicates that the program has a high accuracy. The influence of the atmospheric loss mechanism and the accelerating rate of flight on the acoustic characteristics of the focus boom were investigated. The atmospheric loss mechanism can dissipate the acoustic energy in high frequency component and reduce the Perceived Loudness, which indicates that the atmospheric loss mechanism should be taken into consideration for sonic boom focusing prediction.