Akademik Veri Yönetim Sistemi
15th International Conference on Computational Heat and Mass Transfer, ICCHMT 2025, Antalya, Türkiye, 19 - 22 Mayıs 2025, ss.48-58, (Tam Metin Bildiri)
Flow quality at the engine face, in particular total pressure distribution and swirl characteristics, is critical for the aerodynamic performance and stability of external compression supersonic inlets. Shock wave boundary layer interactions (SBLI) inherent in these inlets often cause flow separation, resulting in degraded performance, increased distortion including detrimental swirl patterns, and potential instabilities such as buzzing. Boundary layer bleed systems are commonly used to reduce the effects of SBLI. However, their specific effects on swirl distortion profiles under different operating conditions have not been comprehensively documented. In this study, the effects of a boundary layer bleed system on the swirl characteristics within a single-ramp external compression supersonic intake are investigated computationally. The performance and flow characteristics for the configurations with blee (WB) and without bleed (WOB) are compared at the freestream Mach numbers of 1.6, 1.8 and 1.9, covering a range of the engine face Mach numbers (MEF), by performing previously validated CFD simulations based on the Realizable k-ε turbulence model. The results show that the bleed system significantly improves the stability margin of the inlet. Specifically, the minimum stable MEF (buzz onset) is reduced in all cases of the freestream Mach numbers investigated. In conjunction with this extended stable operating range, the pressure recovery (PR) near the new stability limit with the bleed shows a significant improvement over the non-bleed case at the same MEF. In addition, under a variety of conditions, the bleed system effectively suppresses the swirl distortion. At the highly distorted and low MEF condition, the bleed system reduces the peak swirl angle range significantly. Similar significant reductions in the peak swirl are also observed at the low MEF condition for higher speeds. The results show the critical role of the bleed system in simultaneously improving the stability margin of the inlet and the pressure recovery near the stability limit and reducing the swirl characteristics, thereby improving the overall flow quality delivered to the engine in supersonic flight regimes.