Pressure drop in pipe lines for compressed air: comparison between experimental and theoretical analysis

Abstract

In this paper a test methodology to determine the flow parameters, such as pressure drop and flow-rate, in straight pipes for compressed air is presented. The experimental test were carried out using a properly instrumented test bench and the curves pressure drop vs. flow-rate, varying the upstream pressure, were obtained. The tests were made on pipes with different internal diameters, corresponding to common industrial size. A theoretical analysis of the pressure drop losses was carried out taking into account Blasius and Prandtl formulations. This approach provides a formula that, considering the roughness and the internal diameter of the pipe, the test conditions (pressure, temperature, density), allows us to calculate the pressure losses at different flow-rate. The formula permits us to calculate the theoretical curves (pressure drop vs. flow-rate) which are in a good agreement with the experimental ones.