Flow rate/pressure in a venturi

[GBA13]

Homework Statement

Hi Guys,

I have found that as flow rate increases the pressure difference in the sections of the venturi increases. Would someone please mind explaining in words why as I'm not sure.

Homework Equations

The Attempt at a Solution

Well I know that when the fluid gets to a constricted section the velocity increases and the pressure decreases but I'm not sure why the pressure difference between the non constricted section and the constricted section increases with increased flow rate.

Thanks very much

 

[DEvens]

http://en.wikipedia.org/wiki/Venturi_effect

 

[GBA13]

http://en.wikipedia.org/wiki/Venturi_effect

I've looked at that but I can't find the answer. Is it there but I'm just missing it?

 

[rude man]

Homework Statement

Hi Guys,

I have found that as flow rate increases the pressure difference in the sections of the venturi increases. Would someone please mind explaining in words why as I'm not sure.

Homework Equations

The Attempt at a Solution

Well I know that when the fluid gets to a constricted section the velocity increases and the pressure decreases but I'm not sure why the pressure difference between the non constricted section and the constricted section increases with increased flow rate.

Thanks very much

Think Bernoulli: p + ρv² = constant if there is no change in potential energy