Abstract
A fondamental difficulty in the experimental study of gravity-driven flows using particle image velocimetry (PIV) and other optical diagnostic techniques is the problem associated with variations in thé refractive index within the fluid. This paper discusses a method by which the refractive indices of two fluids are matched while maintaining density differences of up to 4%. Aqueous solutions of glycerol and potassium phosphate are used to achieve precise index matching in the presence of mixed and unmixed constituents. The effectiveness of the method is verified in a PIV study of a laboratory-scale model of an atmospheric microburst where planes of two-dimensional velocity vectors are obtained in thé evolving flow field.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 434-440 |
| Number of pages | 7 |
| Journal | Experiments in Fluids |
| Volume | 17 |
| Issue number | 6 |
| DOIs | |
| State | Published - Oct 1 1994 |