About the method of research of hydraulic coefficients friction in pressure pipelines

Анотація

When analyzing the existing dependences for the calculation of resistances in pressure pipelines in turbulent mode, significant shortcomings of these recommendations were identified.

It was shown that the currently accepted calculation formulas give significant deviations from the experimental data, which in turn leads to errors in determining the hydraulic coefficient of friction (up to 40%). This indicates the impossibility of using some common dependencies to determine the pressure loss, as it also affects the inaccuracies in the calculations of pipeline capacity.

Comparing a large amount of experimental data with existing design dependencies and analyzing their shortcomings, it was proposed to use some basic factors (such as hydraulic coefficient of friction in the quadratic resistance region lambda sq. and the relative Reynolds number Re/Re_sq) that more accurately characterize the hydraulic coefficient of friction. And this significantly affects the accuracy of determining the pressure loss. The paper shows the corresponding graphs for these basic factors and proposes analytical dependences for their calculation for different types of pipes.

The conducted research characterizes a new approach to determination of hydraulic resistances in pressure pipelines, and the improved technique allows to calculate more precisely pipelines of different function at movement of different liquids with different temperature.