Variability of focused sonic booms from accelerating supersonic aircraft in consideration of meteorological effects

Abstract

Statistics of the meteorologically induced variability of focused sonic boom characteristics due to unsteady, accelerated supersonic flights were derived. The simulations were performed with an advanced sonic boom software including a numerical solver of the Nonlinear Tricomi Equation modeling the focused sound pressure field around caustics. A one-year set of daily meteorological data along the Northern Atlantic flight corridor was used as input. The statistics comprise the location, strength and geometrical extension of caustics at ground level for assumed flights of a supersonic commercial transport from Paris to New York and back. Caustics only occurred during the acceleration phase above the English Channel for flights from Paris to New York, never during the deceleration phase of return flights. The mean value of the maximum focused overpressure is found to be about 4 times the maximum overpressure for cruise flight at Mach 2 in similar conditions, but shows a large variability. The caustics intersection with the ground varies between 3 and 8km in width and between 30 and 180km in length. A linear correlation analysis showed the relationship between meteorological profile shape parameters and the focused sonic boom characteristics.