Hydraulic Lab · Hydraulic jump

Flume 4.30 × 0.30 × 0.45 m

Drag to orbit · scroll to zoom · schematic roller and position

Approach Froude number

Conjugate depth (m)

Ideal energy loss (m)

Energy dissipated

Longitudinal water profile

Blue: schematic water surface · brown: bed · white: entered readings. The roller curve and location are illustrative; the conjugate depths and energy loss are analytical predictions for a free jump.

Observation sheet

Fix slope at 0.002, vary discharge, and adjust tailwater. Record upstream station 0, jump toe 1, and end 2. Compare measured jump length and energy loss across trials.

Q m³/s	y1 m	y2 m	Fr1	Fr2	Length m	ΔE m	ΔH m

Flow & tailwater

Discharge Approach depth Tailwater / conjugate depth

Tailwater mismatch indicates upstream/downstream movement qualitatively. A submerged jump requires a different solver. It is not treated as a free jump here.

Station readings

Jump classification

Equations & limits

Fr1=V1/√(gy1). y2/y1=(√(1+8Fr1²)−1)/2. ΔE=(y2−y1)³/(4y1y2). These are conjugate depths with equal momentum, not alternate equal-energy depths.

Rectangular channel, g=9.81 m/s², hydrostatic end sections, velocity coefficients of 1. The local jump relation neglects bed slope and friction over the roller. The apparatus slope is 0.002; measured ΔH includes the bed drop whereas ΔE compares specific energies.

The displayed roller length uses 6y2 as an illustrative scale. The manual gives a 5–7 depth rule of thumb for barrages without unambiguously defining that depth. This is not a validated length correlation for this flume. No transient turbulence or jump-position solution is computed. Virtual gauges are available only at matched tailwater with a complete free jump inside the flume. Actual readings can be entered for any setting.

Experiment 4 · Hydraulic jump

Longitudinal water profile

Observation sheet