Determination of turbulent pressure loss of non-newtonian oil flow in rough pipes

Summary A detailed theoretical analysis is carried out of the turbulent flow of non-newtonian fluids in rough pipes in which approximate assumptions are of negligible importance. A new friction-factor equation (BNS-equation) is obtained which is valid for turbulent flow of power-law type non-newtonian fluids in the transition region between smooth and wholly rough wall turbulence.The accuracy of the deduced formula was checked by in situ measurements on a crude oil pipeline having a diameter of 305 mm and a length of 161 km. For this pipeline the Reynolds numbers ranged between 10⁴ and 10⁵. The computed and the measured friction factors showed good agreement. The mean of the absolute values of the relative error was 4.1%, while the standard deviation was 0.81%, these results appear to give better fitting than other similar equations published earlier.The BNS-equation is the first analytically deduced relationship for non-newtonian crude oils which includes the effects of both Reynolds number and relative roughness of the pipe.With 6 figures and 2 tables