# Experimental apparatus

1. Jul 14, 2008

### kreil

Introduction

I am a physics major currently working on a summer research project in one of my university's physics labs. Essentially we are studying the physics of channelization...what processes cause channels to form in sand and how the type of flow affects the erosion. The webpage for this project, with a picture of the apparatus, is here: http://physics.clarku.edu/~akudrolli/channels/.

One of the ways we induce erosion is by using several nozzles on a PVC pipe to "rain" water down onto the bed of sand. It is preferable for us to control the flow rate, since too high a flow rate can ruin a trial with flooding.

Problem

The pipe is connected to a typical garden hose which is connected to the sink. I recently noticed that the last nozzle on the pipe opposite from where the hose is attached has a significantly lower flow rate than the other nozzles. (It should be noted that the nozzles are already evenly spaced along the pipe.) This presents a problem, since we want to achieve as even a distribution of water flow as possible.

Also, I recently noticed an engineering problem where one can determine the best spacing of holes on a garden hose so that each hole receives equal pressure...I was hoping that someone could solve/help me solve this problem by determining, for this apparatus, what the ideal spacing of holes is so that each nozzle receives equal water pressure. I am a physics major with zero engineering training.

Specifics

I'm not sure what information is required to solve the problem, but here is some misc. info that will hopefully help (if more is needed please let me know):

Pipe Diameter: 3.2 cm
Pipe Length: 94 cm
Hole sizes in pipe (that nozzles fit in to): 0.9 cm
Approx. water pressure from faucet: 80 PSI

I'm sure this problem is much simpler than I perceive it to be, so please shed some light!

Joshua