Numerical Investigation on the Effect of Height-to-Radius Ratio on Flow Separation Features in S-Shaped Diffuser with Boundary Layer Ingestion

The flow separation occurring in the S-shaped diffuser with boundary layer ingestion (BLI) has a significant effect on performance of embedded engine. Previous studies have found that area ratio (AR) as well length-to-offset (LOR) are key contributing factors affect features. Based phenomena observed previous an 100% BLI, hypothesis parameter height-to-radius (HRR) may also features is proposed. purpose this paper to verify and further investigate HRR BLI using numerical methods. First, verified under uniform inlet condition. Second, investigated different relative heights BLI. It very sensitive change but not height Finally, for fixed generated from airframe, smaller design can significantly suppress thus achieve higher total pressure recovery lower distortion coefficient. results provide improved understandings factor affecting diffuser, useful improving aerodynamic engine