Cut Out Excel SS to help find square inches on circular pit.

[huskerhames]

I have created a spreadsheet that will calculate a sector (area) of a cut out on a circular chamber to match the square inches on the Pit Ratio. It works slick...all you have to do is put in the degrees of an angle til you match the sqare inches of the opening needed between the firepit and cooking chamber. It is easy to calculate on a square bottom, however the circular becomes a chopped sector of a circle. The spreadsheet will give you the cross section distance and the height off of the bottom needed to the reverse flow plate or the tuning plates. I have to post it to a web site first....grrrrrr.

[SoEzzy]

Send me a copy and I'll host the post for you.

Check your PM's
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Here's a change Robert.

I still work here!

[k.a.m.]

huskerhames, now this could be useful. Thank You for the program. And Thank You SoEzzy for offering your services.
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Always remember slow and steady wins the race.

Hybrid Cooker

[huskerhames]

We have used it on three smokers and i am in the process of building another. They seem to be getting bigger everytime.
Soezzy, where can i find the post of the cut out ss? Thanks again!

[Alien BBQ]

Area of a circle= Pi times the radius squared. If it was 3 inches it would be....
A = Pi times r times r
A = 3.14 · (3 in) · (3 in)
A = 3.14 · (9 in)
A = 28.26 in
If you know the diameter then the radius is 1/2 as large.
If you want to figure out the cutout then just divide up the total area into sections (like 8 even sections, count how many sections fits in the desired hole and multiply the fraction by how many sections you have.)
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[huskerhames]

ok alien...the ss gives you the proper height and width of the reverse flow plate. i understand your math, however, this is the area of the sector minus the are of the triangle from the plate. [/b]

[Alien BBQ]

I hope I am understanding your question, in this example the total area of the circle has been divided into 4 sections so the opening (because it takes up 1/4 of the total sections) is 1/4 of the total area. In the case of the 3 inch circle I used before the area of the opening is 7.065...... 28.26 / 4


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[dodis]

Huskerhames,

Finally got a chance to catch up on the forums, and wanted to get a copy of your spreadsheet so I can incorporate that into the full pit ratio calculator spreadsheet. I'll PM you with my email address.

I can see a couple of uses for a sector calculation, as you described, and also to calculate the opening sizes for a round firebox air inlet with an adjustable cover.

I was also thinking before of using a chord calculation to compute the offset value for someone building a round smoker with round firebox, to calculate how much to offset the two pipes to create a firebox to cook chamber opening of the correct size.

I am referencing this thread in the sticky thread for the pit ratio calculator to tie these calculations together.

Mike "Dodis"
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Mike "Dodis"
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UDS (55 gal & converted Old Smokey Electric)
Weber One-Touch
Broil-King Baron
Red"neck"stone Griddle

[SoEzzy]

Sorry for the delay in getting Huskerhames sheet posted.

.xlsx Microsoft Office file

.ods Open Office file
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Here's a change Robert.

I still work here!

[huskerhames]

alien, here is the sector minus the triangle.
[url]http://i904.photobucket.com/albums/ac244/huskerhames/cutout.jpg
[/url]

[Alien BBQ]

Okay, now this will get you real close but not an exact number.

1/2 of "A" = radius

"C" will = 1/2 of total area of circle.

Just to stir the pot, have you factored in eddy currents and flow dynamics?
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