# Openfoam friction coefficient differences.

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 February 8, 2011, 11:07 Openfoam friction coefficient differences. #1 New Member   Peter Join Date: Feb 2011 Posts: 13 Rep Power: 14 He, I am investigating a pipe flow which has the following dimensions. Length 30m, diameter 0.1. A uniform inlet velocity of 10m/s was used as a boundary with a pressure oulet of 0Pa. After simulation. I checked the Yplus. The pressure at the inlet is 285Pa dp/dx is -9.433. With the following formule i calculated the friction coefficient: dp/dx=(-0.5 x rho x 10² x cf) /D cf=0.0154 or something like that. And I would like to have a friction factor of 0.019. Because that is the friction factor that I should have if I fill in my Re, for a smooth pipe situation. I looked this up in a applied fluid dynamic handbook, there is a graph with the friction coefficient vs reynolds number. Anybody has an idea of an increase in pressure, so that my dp/dx becomes 11.7 and therefore my friction factor 1.9? Thank Peter umair458 likes this.

 Tags friction, friction coefficient, openfoam, pressure