File talk:VenturiFlow.png

One problem with this picture is that the caption fails to mention that the horizontal tube of varying area is filled with flowing air, which is assumed to be incompressible. The lower circular tube has some water in it. The relative density of the air and water is important to the understanding of the effect. If the upper tube were filled with water, and the lower tube had oil, with a density that is less than that of the water, then I believe the height would reverse. Please correct me if I'm wrong on this.

Thus one needs to know the conditions to properly interpret the picture.

JontAllen@ieee.org 50.40.97.118 (talk) 21:35, 25 September 2011 (UTC)

Wrong label
We are using this picture in the Pressure head article. The caption is wrong. Instead of "differential pressure" the caption should read "differential pressure head." The meter reads a length measurement, such as inches or mm. And everyone knows that pressure is not measured in length. But guess what? Pressure head is a measurement of length that obviously can be converted to a pressure, but there are other variables.

Hydraulic head is always measured in a gravitational field, so it would be great if this was labeled, too. I like to saw logs! (talk) 10:02, 21 January 2015 (UTC)