- #1

matthew_hanco

- 19

- 0

Pipe before orifice head = 255mm

Diameter = 31.75mm

Pipe after orifice head = 230mm

Diameter= 20mm

Time for 10litres to fill in collection tank 67.09seconds

Assuming g= 9.81 and density = 1000

from the experiment difference in pressure head = 25mm

They wanted to know the theorectical.

Calling everything before head 1 and after head 2

u1= Q/ A where Q= 0.149 x 10^-3 m^3/s and A = 0.791x10^-3 m^2

u1 = 0.188

u2= Q/ A where Q= 0.149 x 10^-3 m^3/s and A =0.314x 10^-3 m^2

u2= 0.475

putting into equaton

P1-P2/p x g = u2^2/2g - u1^2/2g where p=density

gives the difference in theoretical head = 9.7mm

Im not sure if that is right as its a third of the experiment, if it is right how can it be because surely the theory should be higher as you don't take into account the local or frictional losses.

Hope someone can help.