A simple analytical model which can predict accurately the sonic boom pressure signature on the ground in the vertical plane below a supersonic aircraft flying at constant horizontal speed in stratified atmosphere is presented. The proposed model employs geometrical acoustics to propagate the boom and combines a nonlinear treatment of its amplitude with a nonlinear calculation of its distortion, supplemented by the ”area rule” for shocks fitting; ray-tracing equations are derived to calculate the rays trajectory and the ray-tube area, considering the standard atmosphere. Although simple, this combined method allows a very efficient and accurate prediction of the boom propagation starting from a given pressure signal in the near-field and can be considered a useful tool for the aerodynamic design and multi-objective optimization of low-boom supersonic aircrafts via CFD methods. Comparisons with recent experimental data and previously published results obtained via well established sonic boom propagation codes are provided.
Sonic Boom Propagation with a Nonlinear Geometrical Acoustic Model
VIGEVANO, LUIGI
2011-01-01
Abstract
A simple analytical model which can predict accurately the sonic boom pressure signature on the ground in the vertical plane below a supersonic aircraft flying at constant horizontal speed in stratified atmosphere is presented. The proposed model employs geometrical acoustics to propagate the boom and combines a nonlinear treatment of its amplitude with a nonlinear calculation of its distortion, supplemented by the ”area rule” for shocks fitting; ray-tracing equations are derived to calculate the rays trajectory and the ray-tube area, considering the standard atmosphere. Although simple, this combined method allows a very efficient and accurate prediction of the boom propagation starting from a given pressure signal in the near-field and can be considered a useful tool for the aerodynamic design and multi-objective optimization of low-boom supersonic aircrafts via CFD methods. Comparisons with recent experimental data and previously published results obtained via well established sonic boom propagation codes are provided.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.