Toward Sustainable Management: 2D Modelling of a Self-Cleaning System to Improve Geometry in Front of the Flushing Gate

Luis Ruiloba,Beniamino Russo,Manuel Gómez,Gyewoon Choi,Dongwoo Jang

doi:10.3390/su10030745

Abstract

This paper aims to show how numerical modelling based on 2D SWE can be used to analyze the cleaning effectiveness of flushing waves in storm tanks. The case study under consideration is an existing storm tank located in Badalona, a municipality of Barcelona, Spain. Storm tank cleaning systems are critical features that must be carefully addressed. If not appropriately addressed, operation and maintenance work costs can drastically increase. There are numerous currently available technologies for cleaning storage tanks. However, no specific guide on this field has been identified. References are provided by the manufacturers through their commercial catalogues. Generally, this information is not based on experimental or numerical experiences or results have not been published in the literature of scientific papers. In this study, a public domain software (IBER) was used to develop 2D hydraulic analysis of the selected tank. The results obtained show how the phenomenon of recirculation is acting in some areas of the lane. This implies a dissipation of energy, thus causing difficulties in terms of cleaning procedures. Furthermore, two new scenarios have been tested to determine how a different lane width might affect hydrodynamic behavior. A newly suggested geometry for the existing lane of the tank is proposed by using the numerical modeling software. The proposed geometry in the current pilot tank achieves higher velocities and avoids recirculation areas. The results demonstrate that numerical modelling of these types of processes is possible with the computer models available (commercial codes) and can be used to optimize cleaning system design.

Highlights

Climate change is leading to an increase in extreme weather conditions around the world
The results demonstrate that the proposed geometry provides velocities 1.25 times higher in the middle of the lane; cancels the phenomenon of recirculation; and gives higher bed shear stresses
The recirculation areas are produced due to a dissipation of energy when flow water occupies the sides of the lane

Summary

Introduction

Climate change is leading to an increase in extreme weather conditions around the world. One example is patterns of extreme rainfall. This challenges the current sewer system, not least because an increase in rain intensity of 40% to 60% will decrease the return period of flooding events [1]. A growth in urbanization has led to an increase in the use of storage tanks, both to mitigate flooding problems and to reduce discharge to receiving media (known as CSOs, or Combined Sewer Overflows, in the case of combined sewers) [2,3,4]. The tank where the retained poWlluatsehdinmgateefrfiiacliewnilclybeissdtoerpedenudnetinl tcoomnpsrteohremnswivaetcelreatnainnkg d[5e–s8i]g. N. Storm water tanks are often built out of cWonacsrheitneg, aefffliceixeinbclye ims daetepreinadl ewnthoicnhsmtoramy awsastuemr teanmk adneysigfonr. Storm water tanks are often built out of cWonacsrheitneg, aefffliceixeinbclye ims daetepreinadl ewnthoicnhsmtoramy awsastuemr teanmk adneysigfonr. mStosrtmo fiwtatheretsapnakcseasreavofatielnabblueil[t1]

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Methods

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Conclusion