HYD-31

Torricelli efflux

v = √(2 g h). Ideal speed of a free jet under head h.

Reading speed

OrificesTorricelli

Governing equation

v=\sqrt{2gh}

where

h: Head (m)
v: Ideal speed (m/s)

Lecture brief

Historical brief

Open-channel and pipe flow were written by Chezy, Manning, Darcy and Weisbach in the nineteenth century, then Bakhmeteff and Bélanger on the hydraulic jump. The sheets compute conveyance, head loss and gradually varied profiles. This sheet (HYD-31 — Torricelli efflux) is the form associated with Torricelli. Working symbols: $h$ $\rightarrow$ $v$ . Bernoulli with a still free surface and atmospheric jet. Real jets take Cv ≈ 0.97.

Purpose

Purpose: compute

v

from

h

in Hydraulics via

v=\sqrt{2gh}

v = √(2 g h). Ideal speed of a free jet under head h. Use it when a real hydraulics question must be answered in SI before a code check.

Live realistic example

In symbols

Live case. Given

h = 4.000\,\mathrm{m}

, the governing relation

v=\sqrt{2gh}

yields

v = 8.859\,\mathrm{m/s}

. A tank, a hole, a falling jet. Move a slider: the numbers are this situation, not a canned story.

Calculator

Inputs

Head h4 m

Outputs

Ideal speed v8.859 m/s

Reading speed

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Narration of this film

A tank, a hole, a falling jet.

Bernoulli with a still free surface and atmospheric jet. Real jets take Cv ≈ 0.97.

Reading speed

Watch on YouTube