homemade flow bench. orifice plate figure

[hubba]

ok. thanks.

[huisjen]

I ran across an excel spread sheet someplace or maybe I modified someone's I am not quite sure. It seems to take just the deta P across an orifice and come up with the flow. I see may orifice style designs use a % of know flow on an incline manometer.

Can someone look over this sheet and tell me if it is actual flow based on the math or is in % of the plate?
Also I was looking at a fan type transduced from Dakota instruments that I feel I could install in a 3 inch PVC tube. It seem to read velocity and CFM has anyone used such a device in design of a DIY bench?

Perfect numbers are not so important to me but consistency is I only want to take baselines and know I am going the correct way with port work as it progresses and maybe final number for a % of improvement.

I have attached the excel sheet

[86rocco]

I find the layout of that spreadsheet a little awkward but is works well, the flow rate is calculated directly from the differential pressure and orifice size not as a percentage. I put a few numbers into it and the results are consistent with the one I get from my spreadsheet. BTW, there's a link to my sheet in jfholm's post earlier in thread.

[huisjen]

Thanks that is what I remembered. I just wanted someone to look it over and confirm the math is sound. Now I just need to decide what layout to make this and get some Orifice plates made.