11. Discuss fringe formation and its utility in LDV.

12. How is frequency shift determined from scattered light signals falling on the receiver.

13. Describe the principle of operation of a particle image velocimetry system (PIV). List the components used and explain their functions. Separately discuss 2- and 3-component velocity measurement. The review articles by Adrian as well as the chapter in the book by Goldstein (1997) will be useful.

14. Compare advantages and disadvantages of pitot static tube, HWA, LDV, and PIV in the context of velocity measurement. Comment on spatial resolution, speed of response, linearity, and sensitivity to room temperature fluctuation.

15. Develop computer programs for obtaining particle displacement from PIV images. Consider the cross-correlation route as well as autocorrelation.

16. Discuss image processing operations that can help remove spurious velocity vectors from a velocity vector field.

17. For flow past an object, say a cylinder, discuss the measurement of the time dependent flow field and hence the calculation of the time-averaged drag coefficient using PIV data.

18. In Problem 17, discuss laser sheet orientation and camera positions if secondary flow is to be recorded.

19. Newer configurations of a PIV system such as stereo-PIV, 3D-PIV, and tomographic PIV have been proposed in the literature. Study their capabilities and limitations. Discuss algorithms used in each context.