otilla
Mechanical
- Jul 27, 2014
- 1
Hello everyone,
I have a problem in calculation of a system (figure) in which a pump is pumping fluid (Q0) into a pipe dividing into several branches. I would like to count which flow should I have at inlet (Q0) to achieve defined pressures 1 and 2. I assumed that the flow Q0 will split in two equal jets Q1 = Q/2 and Q2 = Q/2, which I know is not correct, because of different heights and losses. But I needed to assumed sth to calculate velocities, Reynolds number and losses in the flow.
I made an equation from Bernoulli law:
p0 + (ro*v0^2)/2+ro*g*h0 = p1 +(ro*v1^2)/2+ro*g*h1 + losses1 = p2 + (ro*v2^2)/2+ro*g*h2 + losses2
by losses I mean: (lambda*ro*l*v^2)/2d + (dzeta*ro *v^2)/2
I have assumed p1=200mbar, so for the first outlet the inlet pressure should be:
p0= 200mbar +(ro*v1^2)/2+ro*g*h1 + losses1 - (ro*v0^2)/2 - ro*g*h0
for p2 = 100mbar, inlet pressure should be:
p0= 100mbar +(ro*v2^2)/2+ro*g*h12 + losses2 - (ro*v0^2)/2 - ro*g*h0
Is my thinking correct? How can I count the inlet mass flow? Any help will be appreciated.
I have a problem in calculation of a system (figure) in which a pump is pumping fluid (Q0) into a pipe dividing into several branches. I would like to count which flow should I have at inlet (Q0) to achieve defined pressures 1 and 2. I assumed that the flow Q0 will split in two equal jets Q1 = Q/2 and Q2 = Q/2, which I know is not correct, because of different heights and losses. But I needed to assumed sth to calculate velocities, Reynolds number and losses in the flow.
I made an equation from Bernoulli law:
p0 + (ro*v0^2)/2+ro*g*h0 = p1 +(ro*v1^2)/2+ro*g*h1 + losses1 = p2 + (ro*v2^2)/2+ro*g*h2 + losses2
by losses I mean: (lambda*ro*l*v^2)/2d + (dzeta*ro *v^2)/2
I have assumed p1=200mbar, so for the first outlet the inlet pressure should be:
p0= 200mbar +(ro*v1^2)/2+ro*g*h1 + losses1 - (ro*v0^2)/2 - ro*g*h0
for p2 = 100mbar, inlet pressure should be:
p0= 100mbar +(ro*v2^2)/2+ro*g*h12 + losses2 - (ro*v0^2)/2 - ro*g*h0
Is my thinking correct? How can I count the inlet mass flow? Any help will be appreciated.