The discussion revolves around determining the appropriate formula for calculating the friction factor in fluid flow through pipes, specifically addressing the von Karman and Prandtl laws for both rough and smooth pipes. The original poster seeks guidance on which formula to apply given the lack of specification regarding the pipe's surface condition.
Participants are exploring different approaches to the problem, including calculating the Reynolds number and comparing friction factors for both pipe types. There is no explicit consensus on which value to choose, as the discussion is still ongoing and participants are seeking further input.
The original poster notes that the problem does not specify whether the pipe is smooth or rough, which is a critical factor in determining the correct formula to use. Additionally, there is mention of using a scientific calculator to derive values for the friction factors.
well , i have found that the f for rough pipe is 0.017 , nut i am not sure how to find f for smooth pipe using von karman and Prandlt laws ... for smooth pipe , i have 1 / ( surd f ) = 2 log [(3.72 x 10^5) (surd f ) / 2.51 ]BvU said:I was going to propose you do both (assuming some reasonable ##e## for galvanized ion pipe ) and compare ...
On the other hand, you do have the data to calculate Re so I certainly wouldn't leave out that one...
so , do you have any comment on this question / which is correct ?Nidum said: