Sonic-Boom Prediction of a Scaled Low-Boom Demonstration Aircraft Considering Viscosity Effects

Viscosity effects in sonic-boom prediction are investigated using inviscid and viscous CFD analysis for estimating near-field pressure signatures of a scaled low-boom demonstration aircraft. A structured/unstructured overset grids method used with Euler CFD analysis is extended to Navier-Stokes analysis for this study. A viscosity effect is shown in the near-field pressure signatures especially in the wing part as a wing thickness effect. This study suggests that the viscosity effects are not critical in low-boom design even for a scaled airplane with small Reynolds number.