SONIC-BOOM OF THE OBLIQUE FLYING WING

This article presents an analysis of oblique flying wing sonic boom characteristics. This long asymmetric wing provides a reduction in sonic boom loudness as well as aerodynamic and structural improvements over conventional transports. The wing is represented by an oblique line equivalent area distribution, a panel model, and a high-definition surface model. The near-field pressure signature of the first two representations is found using the Whitham F-function method applied to the oblique equivalent area distribution and the panel model. The near-field pressure distribution of the high-definition surface model was found using TranAir, a full-potential analysis code. Good agreement between the methods was found. The near-field signature is extrapolated through the standard atmosphere by the Thomas waveform parameter method. The asymmetry in the geometry leads to an asymmetrical sonic boom under the flight track. The bow shock amplitude is typically between 50-75 N/m(2) depending on the size, weight, and altitude of the configuration. The aft shock has only one-half the amplitude of the bow shock due to favorable volume-lift interference. This article also includes a simple method to estimate the maximum sonic boom overpressures of oblique flying wings.