# Flow in branch pipe

## 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 ?

## The Attempt at a Solution

BvU
Homework Helper
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 pa > pb it will flow, up or down or sideways from a to b - as long as there is a path!

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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 pa > pb 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
Homework Helper
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 ?

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
Homework Helper
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 ?

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 ?