The numerical development of MOC for analyzing the inclined pipelines using the experimental network of Babol Noshirvani University as a case study

Abstract

Despite the applications of the MOC for analyzing the unsteady flows, using this method in networks with variable elevations still has many challenges. In this paper, by developing modified correlations as a computer code, the possibility of analyzing inclined pipelines has been evaluated. For validation and calibration, the results of MOC were compared with the results of EPANET software as well as experimental data. To extract experimental data, the water network of NIT with a constant head of 7 m three loops, and four inclined branches were employed. While evaluating the capabilities of the developed computer code, the results show that for all pipes, as the number of pressure fluctuations in a specific period increases, the intensity of the pressure fluctuations decreases, and the damping speed increases as well. Moreover, in inclined pipes, unlike noninclined pipes, the intensity of pressure fluctuations will increase as the elevation increases and the cross-sectional distance from the transient event increases as well. The evaluation of the effect of space steps on the accuracy of the solution to the MOC shows that in the study network, considering 20 segments for each pipe, the fastest response time with an error of less than 1% is obtained.

Evaluation of service pressure regulation strategy on the performance of a rural water network based on pulse demand; using the method of characteristics

“…MOC discretizes and solves the hyperbolic partial differential equations (PDEs) governing the transient flow into four ordinary differential equations by the finite difference method. Simplicity and reasonable accuracy in solving equations, especially problem solving of one-dimensional unsteady flow with constant wave velocity, is one of the advantages of this method (Negharchi & Shafaghat 2021).…”

“…Considering the two dynamic terms of unsteady loss and dynamic effect of pipe-wall viscoelasticity, these equations are PDEs. Assuming a volume of control and using the Reynolds transport theorem, the equations mentioned can be derived as Equations ( 4) and ( 5) for a differential component of the fluid flow (Negharchi & Shafaghat 2021):…”

“…The slope along the pipeline is defined according to Equation (8). Equations ( 9) and ( 10) are used to explain steady and unsteady state friction, as well as the mechanical model to evaluate the viscoelastic behavior of the conduits (Negharchi & Shafaghat 2021).…”

“…4,000) were employed. The effects of unsteady friction fluctuations are also simulated based on the momentary local acceleration and momentary transitional acceleration (Negharchi & Shafaghat 2021).…”

“…Transient phenomena are then created and propagated through the network, which may lead to water quality problems, unequal distribution of resources among customers, and premature deterioration of the pipeline infrastructure (Freni et al 2014). By determining the appropriate spatial step in the pipes and avoiding additional parameters such as pipe elasticity or fluid compressibility, computational effort and complexity are significantly reduced (Kaltenbacher et al 2017;Negharchi & Shafaghat 2021).…”