Sonic Boom Reduction Through the Use of Non-Axisymmetric Configuration Shaping

Abstract

Traditional sonic boom minimization efforts have followed the approach of designing a Whitham “Ffunction” which produced the desired boom signature, followed by development of an airplane configuration representing the same equivalent distribution, and thus boom signature. With the computational resources available today, it is possible to reevaluate the solution approach of many aspects of the boom minimization problem. The near field solution about complex and highly non-axisymmetric configurations may be routinely solved in great detail without the slender body, weak shock, small disturbance assumptions and limitations necessary in the earlier mathematical approaches. Investigations of non-axisymmetric configurations have shown promise when the majority of the disturbance in the supersonic flow field is directed upward, resulting in reduced pressure disturbances, and thus reduced sonic boom below the configuration. CFD analysis and wind tunnel test results on axisymmetric and non-axisymmetric equivalent area distributions have shown good experiment/theory agreement and show that the concept has merit for reducing boom and should be developed further for more representative aircraft configurations.