Experiment 4: May 6, 2010

Setup

This experiment consisted of one 10' Manifold with 1 in. holes drilled every 5 cm on BOTH sides of the pipe. This resulted in an Am/Avenacontracta = 0.5. This ratio was already tested with the 20' Manifold setup, but we were interested to see if the length of the manifold played a role in the flow distribution or if the results for this experiment would be proportional to that of the 20' Manifold setup.

Procedure

The procedure for this test was the same as the procedure for experiment 2. A sample size was chosen (1 in every 5 ports). The Acoustic Doppler Velocimeter (ADV) was then positioned approximately 17 cm from the port being measured. We had attempted to position the ADV closer to the manifold to get a more accurate reading, but we were getting poor readings and thought this might be due to interference of the sonar waves by the PVC pipe. The ADV would be positioned on the edge of this port. Thirty seconds to a minute of data would be recorded, and then it would be shifted to the other side of the port by a centimeter. This process would be repeated until it was ascertained that the ADV had moved out of the range of the port jet (signified by a velocity of, or close to 0 m/s).

This was repeated on each port that was decided to be part of the sample size.

Results

The graph below shows the results from the experiment. The red line indicates the theoretical velocity profile if the effects of pressure recovery were included. The green line indicates the theoretical velocity profile if the effects of pressure recovery were not included. The blue x's indicated the data that we collected for the experiment.

Conclusion