Study of jet-breaker geometric characteristic effects on drop manhole air demand

Authors

1 Postdoctoral Fellow, Department of Hydraulic Engineering, College of Civil Engineering and Architecture, Zhejiang University, Hangzhou 310058, Zhejiang,chine

2 Professor, Department of Civil Engineering, Shahid Bahonar University of Kerman, Kerman, Iran,

10.22125/iwe.2020.114861

Abstract

Drop manholes prevent excessive flow velocity and provide energy dissipation in steep urban sewer and drainage systems. Poor hydraulic performance of them under Regime R2 was improved by jet-breakers. However, they should be still properly sized to efficiently enhance drop manhole operation. In this study, effects of jet-breaker length, width, sagitta, and angel, as well as inlet pipe filling ratio on drop manhole performance, were investigated experimentally. Dimensional analysis and two-level factorial design were utilized to design experiments and analyze drop manhole air demand. Statistical analysis of the results revealed both significant design factors and regression models. Analysis of result determined the proper levels of significant design factors as 80% filling ratio of the inlet pipe, the jet-breaker angel of 70˚, and the jet-breaker sagitta equal to zero. Nevertheless, neither length nor width of jet-breaker had significant effects.

Keywords

References

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Irrigation and Water Engineering
Volume 11, Issue 1 - Serial Number 41
September 2020
Pages 52-65

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