You can download our paper here. Note that some of the more recent reseults are not included. We finish taking data next week! (8/14/07). We will have oscillating and pulsating (three levels of steady flow) and three diffuser angles, all with wide angle and high resolution.

We are making Time Resolved PIV
measurements of oscillating flow through a 30 degree diffuser in the oscillating flow facility.
The test section used for these measurements is shown on the
right. Also in the photo is one of our high-speed cameras (3000
fps). Pressure data is taken in the channel simultaneously. |

We have now generated dozens of avi movies showing how the behavior varies with Reynolds number, displacement Amplitude, and steady flow. These files are now < 7MB. Each one has two successive cycles of the flow. Thanks to Stan Rosen for generating all of these on short order!

No Steady Flow:

R=380, L/h = 11

R=380, L/h = 12

R=380, L/h = 13

R=380, L/h = 15

R=380, L/h = 20

R=580, L/h = 18

R=580, L/h = 21

R=580, L/h = 23

R=580, L/h = 26

R=580, L/h = 30

R=740, L/h = 25

R=740, L/h = 28

R=740, L/h = 31

R=740, L/h = 35

R=740, L/h = 40

Side by Side Compaisons

Re = 380, Lo/h = 11 and 20 (this one is dramatic)

Lo/h ~ 19, Re = 380 and 580

Lo/h ~ 27. Re = 580 and 740

Re = 580, Lo/h = 18 and 30

Steady flow added u0/umax = 1, R380, L/h = 20

ZOOMED IN DATA

The movies show zoomed in data for four cases. The data are presented as vector arrows, but at a handful of streawise locations to give the impression of profiles.

Re = 380, Lo/h = 11

Re = 380, Lo/h = 20

Re = 580, Lo/h = 18

Re = 580, Lo/h = 26