1. Instructor: Lichuan Gui
Imaging Techniques for Flow and Motion Measurement Engr 699, Section 81
Instructor: Lichuan Gui
Spring Semester 2011 Tuesdays and Wednesdays 2:00-3:15pm
NCPA class room #1128
Class material available at
EDPIV software available at

2. Fluid Flow Measurement Methods Overview
Imaging Techniques for Flow and Motion Measurement
Lecture 1
Fluid Flow Measurement Methods Overview
Lichuan Gui University of Mississippi 2011

3. Discussion
Why do fluid flows need to be measured?

4. Discussion What variables need to be measured? Velocity Pressure
Temperature
Density ?

5. Discussion Non-imaging measurement techniques: Velocity:
U-tube manometer
Pitot probe
Hot wire/film anemometer (HW/ HF)
Laser Doppler velocimetry/anemometry (LDV /LDA)
Sonic anemometer
Pressure: pressure sensors
Temperature: temperature sensors
Density: reduced from P, T etc.

6. Non-imaging Techniques
Velocity measurement using U-tube manometer
- Calibration required to determine coefficient “c”

7. Non-imaging Techniques
Velocity measurement using pitot probes
2-hole pitot probe (1D)
3-hole pitot probe (2D)
5-hole pitot probe (3D)

8. Non-imaging Techniques
Velocity measurement using HW & HF
Hot wire
Hot film
Hot film

9. Non-imaging Techniques
Velocity measurement using HW & HF
Energy balance
Electric resistance
Heat convection coefficient
Flow velocity
- Different systems: CCA, CVA, CTA
- Calibration required 9

10. Non-imaging Techniques
Laser Doppler Velocimetry/Anemometry

11. Non-imaging Techniques
Summary of the velocimetries
Pitot proble, HW & HF
Point-by-point measurement
Intrusive
Calibration required
LDV (LDA)
Non-intrudsive
No calibration

12. Imaging Techniques Three groups of flow visualization methods
Foreign material added to the fluid flow
Optical methods sensitive to refraction index changes
Foreign energy (e.g. heat or electric discharge) added to the fluid flow

13. Imaging Techniques Visualization of flow direction
Example: Dye lines in water flow
Vortex flow behind a yawed cylinder visualized
with mixture of ink, milk and alcohole

14. Smoke lines around an airfoil model in a wind-tunnel
Imaging Techniques
Visualization of flow direction
Example: Smoke lines in air flow
Smoke lines around an airfoil model in a wind-tunnel

15. Imaging Techniques Visualization of flow direction
Example: Tuft Screen
Trailing vortices behind an inclined delta-wing as visualized by a tuft screen

16. Imaging Techniques Velocity measurement with tracers
Example: Hydrogen-bubble technique
Consecutive rows of hydrogen bubbles indicating
Velocity profiles a flat plat boundary layer

17. Stroboscopic illumination of oil drop in laminar pipe flow
Imaging Techniques
Velocity measurement with tracers
Example: Small particles
Stroboscopic illumination of oil drop in laminar pipe flow

19. Shadowgraph of a sphere flying at M=1.7
Imaging Techniques
Optical methods for compressed flows
Shadowgraph
Shadowgraph of a sphere flying at M=1.7

20. Schlieren photograph around a sphere flying at hypersonic speed
Imaging Techniques
Optical methods for compressed flows
Schlieren Method
Schlieren photograph around a sphere flying at hypersonic speed

21. Imaging Techniques Other methods Summary X-ray & Echo PIV
Molecular Tagging Velocimetry (Seedless velocimetry)
Laser Speckle Photography
Temperature measurement with particle Brownian motion
More
Summary
Full-field measurement (2D & 3D)
Non-intrusive