Shock Wave-Boundary Layer Interaction: Studying the Effects of Shock Waves on Boundary Layers at High Speeds

Abstract

Shock Wave Boundary Layer Interaction (SWBLI), in High-Speed Flows, such as hypersonic flight and re-entry vehicles, is critical for design. The study focuses on the characteristics of high-speed shock-induced transition with a boundary layer, such as boundary layer separation, drag, and heat transfer increase. In this paper computations are carried out with the use of computational fluid dynamics (CFD) of the viscous SWBLI at various shock forces and Mach numbers. The results show that the stronger the shock waves, the greater they cause the flow separation and thermal load on the surface. The report also studies ways to mitigate such adverse effects, including the use of shock tips and active flow control. Such findings would be even more useful in designing high-velocity planes, bearing in mind that shock wave management would be of the essence in improving the aerodynamic and thermal efficiencies.

Introduction

Shock wave-boundary layer interaction (SWBLI) is a key fluid dynamics phenomenon occurring at high speeds, especially near and above Mach 1, affecting aerospace vehicle performance. When shock waves form due to compressibility at high velocities, they cause rapid changes in pressure, temperature, and velocity within the boundary layer. These changes can lead to flow separation, increased drag, and higher thermal loads, all detrimental to vehicle efficiency and safety.

Research has shown that the strength and position of shock waves relative to the boundary layer largely determine the extent of flow separation and resulting aerodynamic issues. Experimental and numerical studies confirm that stronger shocks cause earlier and larger separation zones, increasing drag and heat transfer. This effect is even more pronounced in hypersonic flight (Mach 5+), where thermal and aerodynamic stresses are extreme, posing risks of surface damage.

To study SWBLI, computational fluid dynamics (CFD) simulations using Reynolds-averaged Navier-Stokes (RANS) equations were conducted across Mach 2 to 6. These simulations validated prior experimental findings, highlighting that shock intensity and angle critically influence flow stability, drag, and heat transfer. For instance, slanting shocks create separation bubbles that worsen drag and heat flux.

Mitigating SWBLI involves shock management strategies such as reshaping vehicle surfaces to deflect shocks, active flow control devices (e.g., synthetic jets), and emerging adaptive materials that dynamically adjust shape to control shock interactions. Future research is needed to optimize shock positioning and vehicle design to reduce SWBLI effects, enabling safer and more efficient high-speed aerospace travel.

Conclusion

The boundary layer/shock interaction is an important phenomenon within the high-speed fluid dynamics field and has a significant impact on the aerodynamic design of hypersonic and supersonic vehicles. The paper gives great details of the impact of shock waves in the boundary layers, showing that a more severe shock yields a distinction to a flow at an earlier breach, big drag, and big thermal loads. The findings confer the significance of shock management and flow control methods in alleviating such negative outcomes. Future studies must be devoted to the optimization of shock wave positioning, the discovery of new management shock measures, and the development of better control technologies to better steer high-speed vehicles.

References

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Copyright

Copyright © 2025 Bishnujee Singh. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.