Research progress on aerodynamic design and flow control technologies for boundary layer ingestion inlets

Boundary-Layer-Ingesting (BLI) propulsion technology uses a rear mounted engine to draw in the boundary layer on the fuselage, reducing the airflow velocity at the inlet of the intake duct and the outlet of the propulsion system, thereby achieving efficient flight of the aircraft. Compared to traditional propulsion systems, BLI propulsion systems have the potential to significantly reduce fuel consumption, flight resistance, and pollution emissions, and are a key development direction in the field of aircraft and engine integration in the future. As a specific practitioner of boundary layer ingesting, the performance of the BLI inlet directly affects the comprehensive benefits of the entire BLI propulsion system compared to traditional propulsion systems. Since its emergence, it has attracted widespread attention from scholars and research institutions at home and abroad. Based on this, this article provides an overview of the research background and progress of BLI intake duct technology, with a focus on discussing the aerodynamic design methods, research methods, internal flow mechanism, and internal flow control technology of BLI intake ducts. Finally, based on the analysis and summary of the current research status at home and abroad, the future development of BLI intake duct is discussed.