reverse engineering volume
reverse engineering volume
(OP)
Hello, I am wondering if somebody can help provide me a new way to find the fluid volume of pipes.
Typically I would model a pipe to spec inside NX and find the fluid volume by subtracting the volume of the inner diameter from the volume of the outer diameter. However, this can approach can take time if you have dozens of fittings to calculate. What I want to do is, instead of going through the trouble of modeling to spec, I would much rather take a partially modeled fitting and reverse engineer the volume.
What I mean is, If I have an elbow that has an outer diameter of 4.5 (in^2), and a wall thickness of .1(in^2), and for example sake, a fluid volume of 75(in^2). I need to add a wall thickness of .5 to get the correct volume. Instead of adjusting the model, can we just adjust the volume to accurately reflect a change in the geometry?
Typically I would model a pipe to spec inside NX and find the fluid volume by subtracting the volume of the inner diameter from the volume of the outer diameter. However, this can approach can take time if you have dozens of fittings to calculate. What I want to do is, instead of going through the trouble of modeling to spec, I would much rather take a partially modeled fitting and reverse engineer the volume.
What I mean is, If I have an elbow that has an outer diameter of 4.5 (in^2), and a wall thickness of .1(in^2), and for example sake, a fluid volume of 75(in^2). I need to add a wall thickness of .5 to get the correct volume. Instead of adjusting the model, can we just adjust the volume to accurately reflect a change in the geometry?





RE: reverse engineering volume
Mike Halloran
Pembroke Pines, FL, USA
RE: reverse engineering volume
RE: reverse engineering volume
What you're doing makes sense from an analytical perspective. In the field, you'll probably see enough variation due to construction and fabrication to throw it off. Then the difference in accuracy between the method I described, and the one you described might not be much.
RE: reverse engineering volume
My point was that when you get the 'same' fitting from multiple sources, you may find substantial differences in leg lengths and in the interior and exterior dimensions.
... and hence the interior volume.
I'm sure you can reverse engineer your model fittings to a particular volume, but I'm perplexed how you'll know what the 'real' volume of a real fitting is, except to trust some salesman (bad idea) or to measure a sample, which is subject to its own set of uncertainties.
Mike Halloran
Pembroke Pines, FL, USA
RE: reverse engineering volume
RE: reverse engineering volume
If it is calculating weight on pipe supports then use ID to get cross sectional area and multiply times length and then double it.
If you are trying to calculate a fluid inventory, just use ID and length, the data quality will never be good enough to get a better estimate.
In other words, almost nothing we ever do with pipe requires the precision you seem to be looking for.
David Simpson, PE
MuleShoe Engineering
In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. Galileo Galilei, Italian Physicist
RE: reverse engineering volume
RE: reverse engineering volume
David Simpson, PE
MuleShoe Engineering
In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. Galileo Galilei, Italian Physicist