need help for calculating friction factor
I want to predict pressure drop over a model on a given flow rate.
For benchmarking i took the cylinderical pipe and study the pressure drop for laminar and turbulent flow at various Re.
i am trying to calculate fricition factor from moody chart (f=64/Re for laminar flow) and comparing it with cfx ( f = -(dp/dx)(2d/(rho*V^2)).
but cfx friction factor is almost double in all the cases. i am could not find reason behind it.
inlet- mass flow rate (based on Re)
outlet- static pressure =0
Thanks and Regards
Thank for the suggestiong you gave.
Indeed i am not sure about the y+ values for turbulent flow so i am studying pressure drop of laminar flow in a pipe.
I have taken a sufficient lenght of the pipe to make sure the flow become fully developed and i am calculating the pressure drop of fully developed region. Still i am not getting the right answer.
Why are my results inaccurate? Been asked a million times, check out the FAQ:
i will go through it and it should help :)
regarding friction factor
even if we take total pressure difference is same as static pressure difference
my value is also deviating from expected value i don't know y ?
expected is 0.128 and i am getting 0.145 but i am doing it in fluent plz tell me where am i going wrong ?
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