Discussion of 'Hydraulics of Tangential Vortex Intake for Urban Drainage' by D. Yu and J. H. W. Lee

摘要

The discusser has read with interest this work on tangential vortex intakes, where a systematic 1D approach was proposed. The authors proved that flow features such as the head-discharge relationship or the vortex flow zone may be approximated theoretically. However, other important results including the experimental free surface profiles in the nonprismatic inlet were presented but not further analyzed. The authors argued that due to the energy loss within a hydraulic jump and zones with rapidly varied flow, the 1D approach may not be used. However, as demonstrated by Castro-Orgaz et al. (2008), nonprismatic channel flow may be approximated by a relatively simple approach based on the gradually varied flow theory. The present discussion aims at providing a 1D analysis of the data presented by the authors using this approach, a point so far overlooked in the paper. Limitations for the 1D analysis are highlighted, and questions on features of general interest are asked of the authors.