Hydraulic Resistance to Non-Isothermal Turbulent Gas and Liquid Flows in Pipes

Abstract

An equation for the hydraulic drag coefficient of friction of stabilized turbulent flows in pipes was obtained based on the boundary layer model and the use of universal relations for the characteristics of boundary layer flows. This equation is in good agreement with experimental data for isothermal flows in the Reynolds number Re range of 5·10³–10⁸. The equation contains a structural parameter that can be used to account for the effect of changes in the physical properties of heat transfer fluids on the resistance in the flow cross sections during heating and cooling. For gaseous heat transfer agents, the impact of their atomicity on frictional resistance in non-isothermal conditions is analyzed.