= Two successive hydraulic controls
For two same-height throats carrying the same light-layer <volume flux> and <reduced gravity>, the narrower throat has the larger critical minimum <energy>. A narrower downstream throat can back up and submerge an upstream throat. If the first throat is narrower, it can control discharge and feed a supercritical current through the second; a <hydraulic jump> followed by a second control is also possible when the available energy drop and intermediate geometry permit it. Equal throat widths are a marginal lossless case. Relative width alone does not fix jump position or mixing in the intervening reservoir.
Back to article page
