Automatic shape optimization using parametric CAD applied to sonic boom reduction

Over the recent past automatic aerodynamic optimization has proven to be of great benefit in the design process defining the detailed shape of aircraft. It has shown to significantly reduce its development cost and cycle time. Besides giving a brief overview of the set-up of the overall optimization process, which includes a finite volume Euler flow solver in combination with a discrete adjoint approach, we will focus in the present paper more specifically on the extension of the parametric CAD modeler to cope with a flexible mean line parameterization enabling to handle local and global dihedral and sweep modifications. Geometric constraints related to a multidisciplinary design context will also be addressed. As an application of these new features we concentrate on sonic boom reduction of a supersonic business jet and its impact on cruise performance. Several test cases based on an inverse problem formulation of the near field pressure signature are considered while also conflicting objectives as maximum lift to drag ratio will be taken into account thereby stressing on the multi-objective and/or multi-constrained aspects of the problem at hand.