Experiment 1: February 25, 2010

Procedure

Our experiment consisted of a very simple setup. The manifold we designed is a 10' long, 6" PVC pipe with 1" diameter holes drilled every 5cm. The manifold had water pumped through it at a rate of 3.8 L/sec (roughly 1 gallon/min) and the water flows through a whole 10' section of 6" PVC pipe before it gets to the manifold to ensure that the effects of the pump have dissipated in the pipe. The manifold is suspended 14" above the bed of the flume by U-clamps and the manifold is spaced 7" from the flume wall to make sure that it runs straight in the flume. The ports of the manifold are positioned so that the jets exiting from them run parallel to the bottom of the tank.

The ADV used to take velocity readings was mounted to a beam running across the width of the flume. The ADV was positioned so that it was aimed head on into the ports (so it also lies parallel to the bed of the flume) at a fixed distance of 17 cm from the port openings.

The measurements were taken at 4 different points along the manifold, separated into at close to fourths as possible given the interference of bolts protruding from the walls of the flume. For each port, we manuevered the ADV in front of each port until we thought we were in the the peak portion of the flow. We recorded data for 1 minute and then moved the ADV 1 cm to the left and 1 cm to the right of our first recording point to ensure that we captured the peak flow. We collected data at these points for 1 minute also.

In the analysis of our data, we took the mean of the velocities at each port for all 3 (and sometimes 4) measurements. Then we plotted the velocity profile for each port, assuming a Gaussian profile, and estimated the maximum flow rate at each port. These calculations were than plotted along the length of the manifold to give a velocity profile for the uniform manifold setup.