Flow in branch pipe

1. May 4, 2016

foo9008

1. The problem statement, all variables and given/known data
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 ?

2. Relevant equations

3. The attempt at a solution

2. May 4, 2016

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

Last edited: May 4, 2016
3. May 4, 2016

foo9008

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

4. May 4, 2016

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.

5. May 4, 2016

8. May 4, 2016

foo9008

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

9. May 4, 2016

foo9008

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