Fluid Mechanics for Chemical Engineers with Microfluidics and CFD, Second Edition

Chapter 3. Fluid Friction in Pipes

3.1. Introduction

In chemical engineering process operations, fluids are typically conveyed through pipelines, in which viscous action—with or without accompanying turbulence—leads to “friction” and a dissipation of useful work into heat. Such friction is normally overcome either by means of the pressure generated by a pump or by the fluid falling under gravity from a higher to a lower elevation. In both instances, it is usually necessary to know what flow rate and velocity can be expected for a given driving force. This topic will now be discussed.

Fig. 3.1 shows a pipe fitted with pressure gauges that record the pressures p₁ and p₂ at the beginning and end of a test section of length L. A horizontal pipe ...