抄録
The aim of this paper is to derive the relation between friction factor and the Reynolds number for the pseudo-plastic fluid flow in concentric annular tubes with roughness, which is assumed the model of drilling mud flow in a well, because the estimation methods of the friction factor in the fluid flow are needed.
Based on the estimation methods of the friction factor of Newtonian fluid flow in a circular tube with roughness given by Colebrook and the relation between friction factor and the Reynolds number for the pseudo-plastic fluid flow in a circular tube with smooth wall given by Dodge and Metzner, the relation between friction factor and the Reynolds number for the pseudo-plastic fluid flow in concentric annular tubes with roughness, is obtained as Eq.(21) that is capable of calculating the friction factor in the turbulent flow region of pseudo-plastic fluids in concentric annular tubes with roughness at any values of rheology parameter, relative roughness and Reynolds number by using the subroutine subprogram shown in the appendix.
The relation presented here includes the cases of Newtonian fluid and pseudo-plastic fluid flow in the circular tubes.
