11. The proportionality coefficient is the dimensionless " Darcy friction factor " or " flow coefficient ". 12. The rotational friction factors are rarely observed directly. 13. The Darcy Weisbach equation contains a dimensionless friction factor , known as the "'Darcy friction factor " '. 14. The friction factor for laminar flow of Newtonian fluids in round tubes is often taken to be: 15. The Darcy Weisbach equation contains a dimensionless friction factor, known as the "'Darcy friction factor " '. 16. Stuart W . Churchill developed a formula that covers the friction factor for both laminar and turbulent flow. 17. This was originally produced to describe the Moody chart, which plots the Darcy-Weisbach Friction factor against Reynolds number. 18. This is also variously called the "'Darcy Weisbach friction factor "', friction factor , resistance coefficient, or flow coefficient. 19. This is also variously called the "'Darcy Weisbach friction factor "', friction factor, resistance coefficient, or flow coefficient. 20. Assuming the Fanning friction factor is a constant along the duct wall, the differential equation can be solved easily.
