A Young's fringe analysis technique and its application to laser speckle velocimetry of flow field

A new Young's fringe pattern analysis technique based on multidirectional scanning over a whole image plane was developed. This technique provides a useful method to process effectively those fringe patterns which are heavily modulated by noise as well as with very poor visibility. Application of laser speckle velocimetry and this fringe analysis technique to the flow velocity distribution measurement of a 2D laminar flowfield was experimentally investigated. The measured data are in good agreement with the theoretical results, although the fringe patterns are severely noisy and with low visibility.