1. Turbulence After the Bend
Jeffery Aguiar
Drew Hayes
University of the Pacific
CVL-130 Fluid Mechanics
Dr. Camilla Saviz

2. Presentation Topics Purpose Background theory Experimental design
Results
Analysis
Suggested improvements
Conclusion

3. Introduction
Constructed 3 water pipes that tested the theory of turbulence after a bend
Measured the length of turbulence for each pipe a total of three times
Analyzed results & compared with theory
Implemented & suggested further improvements of the experiment

4. Purpose
Theory predicts that ~20 diameters away from a 90º bend a turbulent regime is witnessed iff the flow is laminar before the bend
After the set length of turbulence the flow then transitions back to laminar

5. Theory Calculate flow rate using manometer Q = Ko(H/G)1/2 where
Ko= Constant
H = displaced height in manometer [in]
G = 1

6. Theory (cont’d) Reynolds Number (<2300, laminar) vd Re =  where
v = velocity [ft/s]
 = viscosity [ft2/s]
d = diameter [ft]

7. Experimental Design Design of a single apparatus
Figure 1- Experimental apparatus used to measure turbulent regime

8. Actual Design
Figure 2- Apparatus used to measure turbulent regime before drilling injection points

9. Procedure Set up the system Check for laminar flow Inject dye
Measure turbulent zone length
Three for each apparatus & three manometer readings
Repeat with varying pipe diameters

10. Results
Figure 3- Plot of the calculated of L/D values versus Reynolds

11. Results (cont’d)
Figure 4- Plot of the calculated of the length of the turbulent regime values as function of pipe diameter

12. Analysis Agreement with the theory (~20)
Direct relationship between l/d values & pipe diameter
Accuracy of l/d values (avg. D=1.03,max D=2.33)

13. Suggested Improvements
Problem
Solution
Wall friction
Smooth pipe (e/d)
Injection point
Longer needle
Transition point
Larger diam. pipe
Air bubbles
Air release valve
Measured Length
Ruler along pipe

14. Conclusion Observed turbulence after the bend
Measured the length of turbulence
Confirmed the theory

15. Now please enjoy our video !
Acknowledgements
Dr. Camilla Saviz
Adrian
Now please enjoy our video !