Effects of model fidelity on indoor sonic boom exposure estimates

Abstract

Commercial supersonic flight is prohibited over land, but this may change in the near future with the introduction of supersonic aircraft that produce a substantially quieter sonic boom. A transient modal interaction model is used to simulate the acoustic and vibration environment inside a large ensemble of residential homes to estimate the range in levels to which residents may be exposed during overflight of low-boom supersonic aircraft. However, the choice of fidelity used in the finite element models of the house structure (e.g., walls, floors, roofs, etc.) may have an impact on these exposure estimates. This presentation documents a recent study in which the fidelity of the structural finite element models was varied. Model fidelity was either an orthotropic panel approximation, in which the stiffening effects of studs were smeared over the entire panel, or a model that explicitly modeled the sheathing and studs. For sonic boom noise, it was found that the orthotropic panel approximation performs well for partitions that have through-the-thickness geometric symmetry, for example walls with two sheathing surfaces. However, the orthotropic approximation does not perform as well for panels with only one sheathing surface, which is typical of floors, ceilings, and roofs.