Roughness Effect on an Unsteady Flow in Pipelines by Profilometry and Imaging Techniques

Abstract

Problem statement: Currently the aero dynamical calculation in gas pipes is carried out under the assumption of steady state conditions. However real steady in a network is scarcely quasisteady. Approach: The unsteady state is governed by non-linear partial differential equations leading to mathematical difficulties. And there are fore gas pipe dimensions are computed at steady state under extreme conditions. Results: In order to precisely describe gas flow closely to real conditions, we suggest characterizing roughness of two pieces removed during the repair of damaged pipes from a gas transport network. Samples roughness characterization is carried out by profilometry (using a stylus instrument) and by imaging techniques procedures to show the roughness effect and its impact for dynamic flow state. In order to approach real conditions, we considered real cases to construct a model and then we proceeded through extensive simulation for twenty four hours to build graphical means for comparing measurement and computed data. Conclusion/Recommendations: The obtained results are in good agreement with those of imaging analysis and in our interpretation we express that during dynamic flow at high rates gas energy lose due to friction inner walls is characterized this loose are more important as the flow is turbulent. Differences are shown between real data values and figures usually exploited. Design and parameter settings of network should be carried out after a thorough dynamical flow study.