Background-Oriented Schlieren (BOS) for Scramjet Inlet-isolator Investigation

[摘要] Background-oriented Schlieren (BOS) technique is a recently invented non-intrusive flow diagnostic method which has yet to be fully explored in its capabilities. In this paper, BOS technique has been applied for investigating the general flow field characteristics inside a generic scramjet inlet-isolator with Mach 5 flow. The difficulty in finding the delicate balance between measurement sensitivity and measurement area image focusing has been demonstrated. The differences between direct cross-correlation (DCC) and Fast Fourier Transform (FFT) raw data processing algorithm have also been demonstrated. As an exploratory study of BOS capability, this paper found that BOS is simple yet robust enough to be used to visualize complex flow in a scramjet inlet in hypersonic flow. However, in this case its quantitative data can be strongly affected by 3-dimensionality thus obscuring the density value with significant errors.

[发布机构] Faculty of Engineering, National Defence University of Malaysia, Kem Sungai Besi, Kuala Lumpur; 57000, Malaysia^1;School of Engineering, University of Glasgow, James Watt South Building, Glasgow; G12 8QQ, United Kingdom^2

[效力级别] 机械制造 [学科分类] 航空航天科学

[关键词] Background oriented schlieren;Data processing algorithms;Direct cross correlations;Exploratory studies;Flow diagnostics;Flow field characteristics;Measurement sensitivity;Quantitative data