Calculating Minor Head Losses for Pumped Liquid System | Fluid Dynamics Question

[fowler2k]

I have a question where I have to find minor head losses for a system using both the equivalent length method and number of velocity heads method .

It will not let me attatch the drawing here but , a liquid is to be pumped from an underground vessel (which is vented) to a pressurissed container (200KPa absolute) above ground level. The system has 4 x 90 degree bends.
For the equivalent length method using the following data , (standard bend =37 eq length as pipe diameters , entry to pipe = 15 eq l as pipe diameters and exit from pipe = 50 eq l as pipe diameters ) I have worked out the answer to be 0.703m

This is using the modified Darcy equation , assuming typical pipe friction coefficient to be 0.005 and u^2 is 3.24 .

Can anybody please confirm whether this is correct or incorrect please and any feedback would be grateful

Regards

 

[Valkarie]

For the number of velocity heads method, you need to know the velocity of the liquid in the pipe. Assuming it is 1.5 m/s, then the minor head loss would be 0.7 m. This is calculated by multiplying the number of bends (4) by the velocity head (0.18 m).