Tracking background-oriented schlieren for observing shock oscillations of transonic flying objects

Area of Science:

• Fluid dynamics
• Aerophysics
• Optical diagnostics

Background:

• Understanding high-speed flight is crucial for forensic analysis.
• Conventional methods struggle with high-resolution, long-duration measurements of unsteady shock waves in transonic flight.
• Visualizing complex aerodynamic phenomena like shock oscillations requires advanced techniques.

Purpose of the Study:

• To develop and demonstrate a novel tracking background-oriented schlieren (BOS) method for high-speed flying objects.
• To overcome limitations of conventional optical visualization for transonic flight phenomena.
• To enable high-resolution, long-duration measurements of unsteady shock waves.

Main Methods:

• Implementation of a mirror-based high-speed optical axis controller.
• Utilization of a striped retroreflective background for enhanced BOS imaging.
• Integration of predictive trajectory compensation and high-speed silhouette recognition for visual feedback.
• Development of a BOS visualization process using reference image generation from measurement images.

Main Results:

• Successful experimental observation of shock oscillations in an actual high-speed flying object.
• Demonstration of the tracking BOS method's capability for dynamic aerodynamic phenomena.
• Validation of the integrated system for high-resolution visualization.

Conclusions:

• The proposed tracking BOS method is effective for visualizing unsteady shock waves in high-speed flight.
• This technique offers a significant advancement over conventional methods for aerodynamic flow visualization.
• The findings have implications for forensic science and aerodynamic research.