Hits:

Indexed by:Journal Papers

Date of Publication:2015-11-02

Journal:JOURNAL OF HYDRAULIC RESEARCH

Included Journals:SCIE、EI、Scopus

Volume:53

Issue:6

Page Number:787-796

ISSN No.:0022-1686

Key Words:Critical submergence; free surface vortex; particle image velocimetry (PIV); velocity distribution; vortex core radius; water surface profile

Abstract:To study the characteristics of the vortex at a hydraulic intake, an experiment with a free surface vortex was conducted in a cylindrical tank. The vortex flow field was measured using particle image velocimetry (PIV) and extensive experimental data describing the vortex characteristics (radial and tangential velocity distributions, vortex core radius variation, water surface profile and circulation distribution) have been obtained and analysed. Based on the detailed experimental data, an empirical model describing the key vortex characteristics is developed. In addition, using the pressure distributions inside and outside the vortex core, a dimensionless equation for the critical submergence requiring only the Froude number and the circulation number is derived. Results using this equation are in agreement with the experimental data.