Sonic boom focus modeling of benchmark cases using the PCBoom suite Free

Focusing of sonic booms is a phenomenon that can arise from particular atmospheric conditions or aircraft trajectories including acceleration, turns, or other variations from steady level flight. Because such maneuvers are unavoidable, development of regulations for civil supersonic flight will depend on the capability to understand and predict the scenarios in which focus booms can lead to ground overpressures several times higher than typical carpet booms. Models for predicting sonic boom focal zones and focus boom signatures have been developed by several organizations, and a recent AIAA Sonic Boom Prediction Workshop provided an opportunity to compare results among such models. Rallabhandi et al. developed benchmark cases to further extend verification of focus boom models. The PCBoom suite of tools, including the lossy nonlinear Tricomi equation (LNTE) module, was used to predict caustic geometry and pressure signatures near the caustic arising from a constant acceleration level trajectory and also from an accelerating climb trajectory. A recently developed methodto streamline the focus boom modeling process within PCBoom was exercised as part of this benchmark case evaluation. [Work supported by the National Aeronautics and Space Administration under project VXAHA321.]