Ok thank you Katmar for the provided link.
The closest geometry being the corrugated pipe, it seems corrugated pipe correlations should be used instead ...
So nobody can explain why the formula e=ID/250 for a flexible pipe is used?
(http://www.eng-tips.com/viewthread.cfm?qid=69578&page=20)
Hello Katmar,
I am talking of a flexible pipe used in the subsea oil and gas industry like this one http://www.nktflexibles.com/en/Products+and+Solutions/Materials+and+Profiles.htm
The carcass profile is the problematic geometry here. I wanted to know if there is another way of calculating...
By the way using this website http://www.gates.com/index.cfm?location_id=3042, try calculating your pressure drop with same reynolds for two different ID. Using the resulting pressure drop, and the data input, calculate the darcy friction factors ... you will find out that watever the ID, it's...
Well since I don't really like to use a program that does not give me informations on how it calculates , it's not what I'm looking for ...
Is it a flexible pipe, is it a flexible hose, how does it calculate those results ?
Thanks BigInch, I also thought it was e=1/250 but since I found this exact formula in this forum and in the subsea engineering handbook (Q.Bai & Y.Bai) and in other places as well. So I am at my wit's end.
What do you mean by i-one ? ID-1?
To ione thanks for your answer, I guess now you...
I know ! I think I have written it before, in the post before your first one ...
Like I said and like you said, the relative roughness pipe is e/D with e = absolute roughness (in the case of flexible pipe it's apparently ID/250 see: Mark62...
Thank you but I don't really see the relation to what I'm asking. If I understand right, he says that there is a low variation between different roughness, so an error in the roughness does not have that much impact. However, in my case, using a formula like that ID/250 for absolute roughness...
Thanks for your answer,
However, for me, the issue is that you use a ID-dependent absolute roughness that begets a ID-independent relative roughness since in Moody diagram, we use the e/D relative roughness.
For example,
You have a flexible pipe with ID=8"
The absolute roughness is e=ID/250...
Hello everyone,
How can I compute approximately the flexible pipe head loss?
I read in this forum that I should be using a roughness of ID(mm)/250 but how can I use this to have the pressure drop.
thank you
Hello everyone,
I read in this forum, that as a first approximation, ID(mm)/250 can be used for pipe roughness... However, how to use this roughness for pipe pressure drop ?