METHODOLOGY AND SOFTWARE DESIGNATED FOR THE CALCULATION OF VALUES OF CHEZY DISCHARGE COEFFICIENT C AND RELATIVE ROUGHNESS COEFFICIENT n WITHIN THE FRAMWEWORK OF RESEARCH OF FREE-FLOW PIPELINES

The article represents a brief overview of the software programme designated for computer-aided calculation of values of the Chezy discharge coefficient. Recommendations are also provided to users of the proposed software. The proposed methodology is designated for the automated processing of the experimental data obtained in the course of the research of free water flows passing through the hydraulic test rig. The methodology is also designated for the identification of the mathematical relation describing the alteration of hydraulic exponents and for the construction of graphs to illustrate the relations describing the free flow inside pipelines, if made of different types of materials that display varied roughness values. The proposed methodology represents a set of successive stages to be implemented. Stage 1. Identification of pressure loss, if the pipeline length is equal to h, and the hydraulic friction coefficient is equal to λ. Stage 2. Calculation of the average flow strength. Stage 3. Calculation of hydraulic friction coefficient λ. Stage 4. Calculation of average filling value h/dave in the beginning and in the end of the experimental section of the water flow; calculation of hydraulic radius Rave. Stage 5. Calculation of С, Chezy discharge coefficient. The following steps are to be performed to calculate coefficient of roughness n: Selection of optimal relation С=f(R) from the multiplicity of proposed relations; Solving the two equations in relation to n. The proposed software employs the half-interval method to identify the value of n. The software is also capable of generating graphs (curves) to describe the relations in question. The proposed methodology and the software designated for the calculation of Chezy and roughness coefficients makes it possible for users to identify the hydraulic properties of pipelines made of advanced materials or having advanced coatings. The availability of the above information is to optimize the selection of the pipeline repair material on the basis of the assessment of hydraulic compatibility between the sections of the pipeline in operation and those being repaired