Temperatures Generated by the Flow of Liquids in Pipes

Abstract

In the development of molecular theories of liquid and polymer structure, great importance is attached to stress and time dependences of the apparent viscosity of materials and their solutions. Some of these dependences can be accounted for by the heating of the fluid which is a consequence of the flow. In this report, solutions for the time and space distributions of the temperature in an incompressible fluid flowing steadily in a capillary with isothermal walls are presented. A comparison of the computed temperature changes with observed changes in apparent viscosity of some lubricating oils suggests that the temperature effect is significant. The possible usefulness of the solutions for understanding the origin of turbulence in flow and the heating of a cylindrical rod loaded in torsion is also discussed.