CDC Meeting Minutes

Summer 2009 Minutes

July 10, 2009

Accomplishments

Learned MathCAD basics (naming and defining variables, creating vectors, creating equations, graphing, default units, and changing them)

Set up and ran an experiment to test the teacup theory (Monroe's theory of how to reduce aeration leading to bubble formation).

Wednesday, Nadia and Alex met briefly and decided that it would be a good idea for the whole CDC team to look at the Flow Control slides from Monroe. Each member was supposed to go over the slides and then attempt to use MathCAD to model the teacup theory, and have the codes for our meeting on Thursday .

Thursday, we met before the team meeting to go over MathCAD codes. We all had worked on individually modeling the teacup theory (using a bucket with an orifice drilled in the bottom), using MathCAD to determine the size of the orifice needed, as well as the height of the bucket.
With the help of Matt, we brainstormed about the placement and size of the bucket that will be needed. Unfortunately we determined that the design of the bucket would not be as simple as originally anticipated (see Issues section below).

Outcomes

From the teacup experiment, we determined that a height from the top of the waterfall to the rim of the cup should be about 14cm in order to reduce the amount of bubbles that overflow into the main tank from the teacup.

We have a number of steps to follow in order to design this bucket:
1) Calculate head loss through sutroweir at Qmax and Qmin.
2) Retrofit bucket design. Calculate size of the bucket so that it is completely submerged at Qmin.
3) Ensure bucket is tall enough so no overflow at Qmax.
4) Recalculate all values while taking water displacement caused by bucket into account.

For next week we need to calculate the distance traveled by the jets of water coming out of the holes in the sutroweir. This will allow us to figure out the maximum possible diameter of the bucket.

Issues

We determined that the bucket theory was going to require a lot more design and planning than we had anticipated due to the complexity of determining the size and placement of the bucket that will catch incoming water in the LFOM. Changing flow rates in the plant change the height of the water in the LFOM, and we need the bucket to be big enough to catch the water and not overflow, but also small enough to fit inside the LFOM.

Goals for upcoming week

We split up the 4 designs between each team member so that we can move faster to find the best retrofit design. We should put these into MathCAD by early next week.
Nadia - Bucket with orifice
Alex - Bucket without orifice
Francine - Inclined and vertical planes
Biniyam - Pipe within the LFOM

Also, we have the midterm wiki due Monday at 5pm. We need to finish that!