Flow in branch pipe

[foo9008]

Homework Statement

in the notes , the author stated that the water from reservoir 1 could flow to reservoir 2 and 3 ..... i dont understand how could the water flow from 1 to 2 through junction D ? how could the water flow from low to high ?

Homework Equations

The Attempt at a Solution

 

[BvU]

Now my response went into the black hole

Don't see no D !

And water flows under the driving force we call pressure ! As long as p_a > p_b it will flow, up or down or sideways from a to b - as long as there is a path!

 

[foo9008]

Now my response went into the black hole

Don't see no D !

And water flows under the driving force we call pressure ! As long as p_a > p_b it will flow, up or down or sideways - as long as there is a path!

do you mean as long as position reservoir A > B , the pressure is large enough for the water to flow upwards?

 

[BvU]

It's a bit more complicated than that because of the presence of reservoir 3.
It's not the position that 'decides', but the pressure.
From the picture I'd conclude that $H_J > h_{f2}$ is the condition for flow towards the second reservoir. For instance if pipe 3 is very narrow.

 

[foo9008]

It's a bit more complicated than that because of the presence of reservoir 3.
It's not the position that 'decides', but the pressure.
From the picture I'd conclude that $H_J > h_{f2}$ is the condition for flow towards the second reservoir. For instance if pipe 3 is very narrow.

##H_J ? what do you mean by it ?

 

[foo9008]

It's a bit more complicated than that because of the presence of reservoir 3.
It's not the position that 'decides', but the pressure.
From the picture I'd conclude that $H_J > h_{f2}$ is the condition for flow towards the second reservoir. For instance if pipe 3 is very narrow.

how to know that if P at A > P at B ?

 

[BvU]

how to know that if P at A > P at B ?

That's exactly what they try to teach you with the picture !
$H_J$ is the total head at J (what you called D, the branching point). Since that depends on the flows and the flows depend on the head differences, they propose an iterative solution method.

 

[foo9008]

That's exactly what they try to teach you with the picture !
$H_J$ is the total head at J (what you called D, the branching point). Since that depends on the flows and the flows depend on the head differences, they propose an iterative solution method.

ok , can i also say it as position of A is the highest , so P/( rho g ) + z has the highest value for A ?

 

[foo9008]

That's exactly what they try to teach you with the picture !
$H_J$ is the total head at J (what you called D, the branching point). Since that depends on the flows and the flows depend on the head differences, they propose an iterative solution method.

i dont understand how could the water flow from q to 3 and Q2 is 0 ?