Robust Low-Boom Design Based on Near-Field Pressure Signature in Whole Boom Carpet

An inverse low-boom design method using a reversed equivalent area Ae,r based on off-body pressure distributions is effective because this method captures three-dimensional effects in a flowfield. In this paper, a robust low-boom design method using Ae,r is proposed to consider off-track sonic boom loudness. Computing costs are reduced by applying multipole analysis, which allows the capture of three-dimensional effects, even when an off-body location is close to a body. In terms of robustness, it is difficult to set feasible target Ae,r distributions in a whole boom carpet. Unfeasible targets may lead to results contrary to the design intent. Thus, the target is imposed only on the undertrack Ae,r distribution. In addition, second derivatives of Ae,r having direct relation to the F function are controlled in the whole boom carpet. As a result, second derivatives are successfully controlled as intended by free-form deformation and genetic-algorithm-based optimization. The undertrack Ae,r meets the target ...