Design of Submerged Air-Intake for UAV Application

The design approach and performance analysis of a custom s-duct submerged inlet are presented in this paper for a stealth subsonic swept-back Unmanned Aerial Vehicle (UAV). The UAV must provide good efficiency in a wider range of operating conditions. The duct is designed in such a way that it is the best compromise between the fuselage-engine framework and should provide maximum pressure recovery. Important geometric parameters of the s-duct inlet consist of a length-to-engine diameter ratio of 5.18, an offset-to-length ratio of 0.12, and an area ratio of 1.89. A review of fundamental concepts and the design process is presented to provide a foundation for future design iterations. METACOMP CFD++ software has been used to analyze the inlet design performance. Pressure recovery and circumferential total pressure distortion are used to analyze inlet performance at zero incidence angle.