*Article* **Internal Aerodynamic Performance Enhancement for Aircraft with High Maneuver by Designing a Distributed Submerged Inlet**

**Junyao Zhang and Baigang Mi \***

School of Aeronautics, Northwestern Polytechnical University, Xi'an 710072, China **\*** Correspondence: mibaigang@nwpu.edu.cn

**Abstract:** Submerged inlet has been widely used in UAVs and cruise missiles due to its good stealth characteristics, but it also brings the disadvantage of poor aerodynamic characteristics. Especially in large maneuvering flight, the flow field near the fuselage has a strong unsteady effect, and the total pressure recovery coefficient and distortion characteristics have deteriorated sharply. In order to investigate the steady and transient aerodynamic characteristics of the submerged inlet in large maneuver flight and improve its maneuver envelope, a design scheme of a distributed submerged inlet for large maneuver flight is proposed in this paper. Taking a cruise missile as the research object, the steady and transient analysis of the conventional submerged inlet and the distributed submerged inlet is carried out using CFD numerical method. The results show that the distributed submerged inlet can significantly improve the inlet performance and enhance the sideslip limit of the submerged inlet during large sideslip maneuver flight. When the sideslip angle is 30◦ , compared with the conventional submerged inlet configuration, the outlet total pressure recovery coefficient of the distributed submerged inlet configuration is increased by 44.2%, and the total pressure distortion index is reduced by 66.3%.

**Keywords:** submerged inlet; large maneuver state; nested mesh; total pressure distortion index; distortion characteristics; hysteresis effect

**Citation:** Zhang, J.; Mi, B. Internal Aerodynamic Performance Enhancement for Aircraft with High Maneuver by Designing a Distributed Submerged Inlet. *Appl. Sci.* **2023**, *13*, 1459. https://doi.org/ 10.3390/app13031459

Academic Editors: Josep Maria Bergadà and Gabriel Bugeda Castelltort

Received: 29 December 2022 Revised: 13 January 2023 Accepted: 18 January 2023 Published: 22 January 2023

**Copyright:** © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).
