Updates to PCBoom Sonic Boom Propagation Code: Modeling QSF18 Sonic Thumps

NASA PCBoom sonic boom propagation code has recently been updated to improve the code's numerical accuracy and efficiency. This paper specifically discusses algorithms for calculating the ray tube area, accounting for turbulence effects, and determining the entire sonic boom carpet. Unlike most existing sonic boom propagation codes that require three or four neighboring acoustic rays for the ray tube area calculation, the updated PCBoom requires only one ray to perform the same calculation. In addition, the turbulence algorithm employed here is based on a multiple-scattering theory rather than based on a oneway parabolic equation used by existing algorithms. Numerical models obtained using the updated PCBoom are compared with a measured dataset from the Quiet Supersonic Flights 2018 research campaign (QSF18) that NASA conducted in Texas in 2018. The dataset was obtained using dive maneuvers performed by supersonic conventional aircraft that generated small-amplitude sonic booms, called sonic thumps, mostly with small elevation angles of arrival. In such sonic booms, the effects due to turbulence and spreading from refraction are significantly large, making the dataset suitable for assessing the code's performance to
accurately predict such effects.