- #1
menco
- 43
- 0
Homework Statement
The pump in the system below has an efficiency of 75%. The atmospheric pressure is 101 kPa and the vapor pressure is 2.3 kPa (in absolute units). Assume kinematic viscosity is 0.96x10-6 m2/s. Neglect minor losses.
a) Calculate the velocity through the main pipe and of the jet
and a few other questions to do with friction factor, etc.
Homework Equations
AV=AV
v^2/2g + P/pg = v^2/2g + P/pg
Have been given the answers but no working. – 9.66 m/s for pipe and 38.64 m/s for jet
The Attempt at a Solution
First used AV=AV to get
v_2 = [(d_1)^2/(d_2)^2] v_1
Then I put this into Bernoulli with the relevant pressures P_1 = 700000, P_2 = 101000 but I only manage to get v_1 = 8.94 m/s.
I have tried working it with elevation head but still can't seem to get the right answer. I am thinking maybe I should have pump head? But not too sure how to calculate with what I have been given.