Hydraulic jumps at drop and abrupt enlargement in rectangular channel

Interdependence Between Flow Pattern, Geometry and Flushing Efficiency of in-Ground Stilling Basin

“…The frequently observed flow patterns within ISB can be summarized into four major families as: B-jump, U-jump, Periodic submerged jump and Steady submerged jump. The definition of the different jumps observed in current study is well described in the past 9) . The previous publication of the authors concerned about the classification of flow patterns within ISB; where it was noted that the type of hydraulic jumps within ISB is less dependent to Froude number at the face of bottom outlet, Fr 1 , and more dependent on the end-sill height at the end downstream of ISB, h e 10) ; similar findings were reported by Kantoush et al 4) and Ohtsu et al as well 5) .…”

Energy dissipation within in-ground stilling basin

“…The possible hydraulic jumps types within ISB classified into 4 major flow patterns as: B-jump, U-jump, Periodic submerged jump and Steady submerged jump. The definition of the different type of jumps that we observed in the current study is well described in the past (Ferreri and Nasello, 2002). Table 2 summarizes the flow patterns with names, characteristics and ISB structure geometry that is required to form each flow pattern.…”

“…Table 2 summarizes the flow patterns with names, characteristics and ISB structure geometry that is required to form each flow pattern. Ferreri and Nasello (2002) pointed out through the mutual effect of a drop and an enlargement, a fully 3D and complex overlapping effect has been detected that in individual presence of each of these measures has not been detected. Katakam & Rama (1998), but, noted that in case of low drop number conditions, which is introduced earlier, the flow patterns within ISB is much referable to those that is observed in only sudden enlargement.…”

Comparison between 2D Shallow-Water Simulations and Energy-Momentum Computations for Transcritical Flow Past Channel Contractions

“…We induce the onset of transcritical flow at the throat section by reducing the distance to the outlet, L d (Figure 15). Both 1D and 2D models predict near-critical flow conditions for hydraulically long channels, L d = 4000, 500 m, and the onset of repelled hydraulic jumps (R-jumps) [26,28] for the shorter distances, L d = 250, 125 m (Figure 15d). The development of the backwater profile leads to a flow pattern downstream of the contraction that is more complex than in the case of a short channel with imposed tailwater depth.…”

“…The subcritical-supercritical-subcritical transition that may occur at a gradual or sudden contraction in horizontal or mildly sloped channels has been thoroughly studied since Khafagi's seminal work on Venturi flumes [24]. For approaching supercritical flow at the channel throat, the key experimental objective has been to understand the structure of the energy dissipation mechanisms in the downstream expansion region [25,26], characterizing the flow morphology and location of hydraulic jumps in the stilling basin through the approach Froude number, expansion geometry and tailwater depth [26][27][28]. In relatively abrupt transitions, where separated flow occurs at the enlargement of the channel width, different jump morphologies have been identified depending on the momentum content of the supercritical and subcritical regions [26,28].…”