{"title":"Numerical investigations of cylindrical weir-gates with a flow extender","authors":"Amirreza Shamsi, Amir Hossein Azimi","doi":"10.1016/j.flowmeasinst.2025.102833","DOIUrl":null,"url":null,"abstract":"<div><div>This study provides a comprehensive analysis on the hydraulics of flow over cylindrical weir-gates with and without a flow extender, utilizing a validated numerical model. The model, validated against recent experimental data, examines the effects of various parameters including the angle of flow extender, gate opening, and submergence levels on flow characteristics, energy losses, and discharge reduction factors. The findings indicate that Results show that weir-gates equipped with a flow extender experience a notable reduction in energy losses—up to 35 % for flow extenders with angles between 0° and 10°, compared to only 19 % for weir-gates without a flow extender. While the modest impact of the flow extender on discharge capacity, it effectively minimizes downstream vortices and energy dissipation. Additionally, three distinct submerged flow regimes (Surface Jump, Surface Wave, Deeply Submerged Flow) were identified, illustrating the behavior of flow with varying submergence levels. The modular limit, marking the onset of submerged flow, decreases significantly with larger gate openings, showing a maximum reduction of 64 %. The discharge reduction factor also varies with gate opening, remaining stable under moderate conditions and then sharply declining with increased submergence. These insights are essential for optimizing the design and performance of cylindrical weir-gates across different hydraulic conditions, thereby enhancing their efficiency and effectiveness in practical applications.</div></div>","PeriodicalId":50440,"journal":{"name":"Flow Measurement and Instrumentation","volume":"102 ","pages":"Article 102833"},"PeriodicalIF":2.3000,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Flow Measurement and Instrumentation","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0955598625000251","RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENGINEERING, MECHANICAL","Score":null,"Total":0}
引用次数: 0
Abstract
This study provides a comprehensive analysis on the hydraulics of flow over cylindrical weir-gates with and without a flow extender, utilizing a validated numerical model. The model, validated against recent experimental data, examines the effects of various parameters including the angle of flow extender, gate opening, and submergence levels on flow characteristics, energy losses, and discharge reduction factors. The findings indicate that Results show that weir-gates equipped with a flow extender experience a notable reduction in energy losses—up to 35 % for flow extenders with angles between 0° and 10°, compared to only 19 % for weir-gates without a flow extender. While the modest impact of the flow extender on discharge capacity, it effectively minimizes downstream vortices and energy dissipation. Additionally, three distinct submerged flow regimes (Surface Jump, Surface Wave, Deeply Submerged Flow) were identified, illustrating the behavior of flow with varying submergence levels. The modular limit, marking the onset of submerged flow, decreases significantly with larger gate openings, showing a maximum reduction of 64 %. The discharge reduction factor also varies with gate opening, remaining stable under moderate conditions and then sharply declining with increased submergence. These insights are essential for optimizing the design and performance of cylindrical weir-gates across different hydraulic conditions, thereby enhancing their efficiency and effectiveness in practical applications.
期刊介绍:
Flow Measurement and Instrumentation is dedicated to disseminating the latest research results on all aspects of flow measurement, in both closed conduits and open channels. The design of flow measurement systems involves a wide variety of multidisciplinary activities including modelling the flow sensor, the fluid flow and the sensor/fluid interactions through the use of computation techniques; the development of advanced transducer systems and their associated signal processing and the laboratory and field assessment of the overall system under ideal and disturbed conditions.
FMI is the essential forum for critical information exchange, and contributions are particularly encouraged in the following areas of interest:
Modelling: the application of mathematical and computational modelling to the interaction of fluid dynamics with flowmeters, including flowmeter behaviour, improved flowmeter design and installation problems. Application of CAD/CAE techniques to flowmeter modelling are eligible.
Design and development: the detailed design of the flowmeter head and/or signal processing aspects of novel flowmeters. Emphasis is given to papers identifying new sensor configurations, multisensor flow measurement systems, non-intrusive flow metering techniques and the application of microelectronic techniques in smart or intelligent systems.
Calibration techniques: including descriptions of new or existing calibration facilities and techniques, calibration data from different flowmeter types, and calibration intercomparison data from different laboratories.
Installation effect data: dealing with the effects of non-ideal flow conditions on flowmeters. Papers combining a theoretical understanding of flowmeter behaviour with experimental work are particularly welcome.