Optimization of pressure-driven bleed–blow loop for controlling shock wave/turbulent boundary layer interactions in supersonic flows

Shock wave/turbulent boundary layer interactions (SWBLI) can induce multiple adverse effects. Building upon studies that demonstrate the effectiveness of a pressure-driven bleed–blow loop (PBBL) as a passive flow control technique, this paper numerically investigates the PBBL method. We propose a novel dual-blowing-slot configuration to control shock wave/turbulent boundary layer interaction more effectively than the conventional single-slot design. The dual-slot design offers superior performance, achieving a significantly greater reduction in separation bubble area and improved flow control, particularly in high backpressure environments, thus providing a more robust solution compared to traditional methods. The results indicate that the PBBL reduces the area of the separation bubble by 80.59% compared to the uncontrolled baseline case. Compared with the single-slot configuration, the dual-slot design significantly enhances the flow control effectiveness, achieving a reduction of up to 55.54% in the separation bubble area. Moreover, as the backpressure increases, the effectiveness of the PBBL in suppressing the peak Stanton number (St_peak) improves progressively. At the Pr4-(2) condition (The backpressure is set to four times the inlet pressure, and the flow field operates for 2 ms.), the St_peak is significantly lower than that in the uncontrolled case, and a reduction of 91.25% is observed. The case without the PBBL solution fails to start under the Pr5-(5) condition, whereas the case with the PBBL solution maintains a stable low pressure at the inlet of the isolator. These results demonstrate that the PBBL, particularly the dual-slot configuration, offers an effective and robust approach for mitigating SWBLI, reducing thermal loads, and improving inlet stability in severe backpressure environments.