Document Type : Original Article


1 Eng. Mohamed Hassan, Structure Design Department Head, Aerospace Research Center.

2 Prof. Dr. Mohamed Madbouli Abdelrahman Aerospace Department, Faculty of Engineering, Cairo University.


The aircraft air intake is one of the most important parts in the layout design of modern fighter and trainer aircraft. Most of the aircrafts famous for their good maneuvers have a well designed air intake, which is capable of tolerating high angles of attack and large sideslip angles without significant pressure losses. The aim of the present work is to optimize the layout of subsonic S-type air intake using seven design parameters through two optimization cycles. The first optimization cycle uses analytical representation of the cost function denoting the total pressure loss in the air intake, and also the physical and geometrical constrains imposed on the design for a complete geometrical compatibility with the external shape of the aircraft. Such representation invokes low fidelity techniques. A genetic algorithm was used for the optimization to obtain an optimal shape of the air intake. The obtained results were used as the initial point for the second optimization cycle based on CFD analysis of the problem, which signify a higher fidelity computational technique. The complete optimization cycle is originated by integrating together all the developed modules, from geometry and grid generation to the final convergence of the solver solution and global optimization.