Focusing on the boundary layer ingestion effects on the rectangular-to-circular S-shaped intake and fan coupling aerodynamic performance

steady and unsteady computational fluid dynamics (CFD) numerical simulation methods were used to analyze the intake and the fan’s aerodynamic performance and the fluid features. The numerical simulation and analysis results revealed the primary effects of the inlet boundary layer ingestion. With the increase of intake boundary layer ingestion thickness

the steady circumferential total pressure distortion index of the intake outlet

the total pressure defect and the relative airflow angle of the distortion regions rose

and the flow coefficient decreased within the total pressure distortion region. However

the size of the intake distortion region changed little

and the inlet boundary layer thickness made minimal effects on the total aerodynamic performance of the intake and the fan. Due to the pressurization effect of the fan

the outlet airflow parameters distortion among circumferential direction was weakened effectively.