If the flow is initially subcritical and the channel slope increases, the water may undergo a hydraulic drop if it transitions from subcritical to supercritical. As water flows down a culvert, the depth may change and pass through the critical depth if the bottom slope, geometry, or pipe material changes. First the the critical depth maximized efficiency in the system) If the depth of the flow is less than the critical depth a hydraulic jump may appear ; Also, the critical flow & critical velocity occur at the critical depth. DEPARTMENT OF THE INTERIOR DONALD PAUL HODEL, Secretary U.S. GEOLOGICAL SURVEY Dallas L. Peck, Director For additional information write to: Chief, Office of Surface Water U.S. Geological Survey 415 … Supercritical flow is shallow, fast flow with a high energy state and has a Froude number greater than one (F>1). Critical Depth of Open-Channel Flow Posted in Hydraulics | Email This Post | For a given value of specific energy, the critical depth gives the greatest discharge, or conversely, for a given discharge, the specific energy is a minimum for the critical depth. BASIC HYDRAULIC PRINCIPLES OF OPEN-CHANNEL FLOW By Harvey E. Jobson and David C. Froehlich U.S. GEOLOGICAL SURVEY Open-File Report 88-707 Reston, Virginia 1988. 350 grant: critical flow constrains flow hydraulics Froude number equals 1 at critical flow; when Fr > 1, the flow is termed supercritical, and when Fr < 1 the flow is subcritical.
The critical depth is the depth where the energy of the flow has been minimized (i.e. Comment on "Critical flow constrains flow hydraulics in mobile-bed streams: A new hypothesis" by G. E. Grant Hubert Chanson Department of Civil Engineering, University of Queensland, Brisbane, Queensland, Australia 1. Critical flow occurs when the Froude number equals one (F=1); there is a perfect balance between the gravitational and inertial forces. Mukherjee-Brill is better for 0.1 < H L < 0.35. Introduction This paper discusses the challenging ideas proposed by Grant [1997] on steep movable bed channel flows.

For gas-dominated two-phase pipe runs with subcritical flow: • Use the Dukler–Eaton correlation, and for cases with very low liquid loadings (<10 bbl/MMSCF, or 0.056 m 3 /1000 s m 3) bracket with the Beggs, Brill, and Moody correlation.