PREDICTION OF CRITICAL SUBMERGENCE FOR HORIZONTAL INTAKES UNDER ASYMMETRICAL APPROACH FLOW CONDITIONS

Abstract

Air-entraining vortices at intake structures present serious challenges to the functionality of water intake systems, resulting in reduced efficiency and possible damage to hydraulic equipment. The present study aims to predict the critical submergence, Sc, which is the minimum vertical distance between the free surface and intake pipe to avoid air-entraining vortices, for horizontal intakes under asymmetrical approach flow conditions. Dimensional analysis was utilized to investigate the influences of intake geometry, approach Froude number, intake Froude number, Reynolds number, and Weber number. Two hundred and twenty-five experimental data for asymmetrical approach flow conditions were evaluated to derive more general and accurate empirical equations predicting the dimensionless critical submergence, Sc/Di. The results indicate that the intake Froude number (Fr)i, and the geometric parameter are the most important parameters that affect Sc/Di. Accordingly, the most accurate empirical equations were obtained while considering all the flow and geometric parameters to predict Sc/Di. On the contrary, the accuracy of the empirical equations considering only (Fr)i gives moderate results in predicting Sc/Di.

Keywords

• Air-entraining vortices
• Approach Froude number
• Critical submergence
• Horizontal intakes
• Intake Froude number.

Supporting Institution

No funding or research grant was received during the review, research or compilation of the article.

Ethical Statement

The authors declare to comply with all ethical guidelines, including authorship, citation, data reporting, and original research publication.

Thanks

The authors thank Prof. Dr. Mustafa Göğüş for his contribution and suggestions during the study.

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