Question 1:

The constant head tank preserves the volume by allowing the water in the reservoir to overflow into the discharge tank, when the water flow is kept constant. This ensures to that the flow is constant. The effects of small changes in fluid level and volume when overflowing are considered negligible. This constant volume tank represents a pressurized hydraulic reservoir, with constant pressure, making the manometer fluid levels constant and accurate during the readings. If the water levels in the constant head tank were to drop suddenly whilst taking the readings, the pressure will drop and the readings on the manometer would be inaccurate.

Question 2:

The Hydraulic grade line is a plot of the hydraulic head (which is the head …show more content…
After manometer 10, the gradient decreases, this is because the velocity of the fluid decreases. This also indicates the increase in losses. The hydraulic grade line increases until before manometer 13 where it suddenly drops where the losses are increased due to the Orifice Plate that significantly reduces the pipe diameter. Manometer 14 and 15 were very unstable as the head fluctuated, this was due to the extremely turbulent flow following the fitting between manometers 13 and 14 as well as the significant increase in the friction losses experienced by the fluid at this …show more content…
D=0.0439m, g=9.81 m/s^2, L=0.6m Run 1 Run 2 Run 3 Run 4 hL (m) 0.045 0.035 0.040 0.035
Vel. Of B, U(B) (m/s) 1.572327067 1.456876467 1.4367816 1.33976
Friction factor, f 0.026123 0.03044 0.031293 0.038928
Reynolds number, Re 103500 98625 98842 96493

Using a Moody diagram the theoretical average friction factor is found to be 0.017 meaning the pipe should be quite smooth. But the average of the four friction factors from the experimental data is 0.031696. The higher calculated value indicates that the pipe is not ideally smooth. The Moody diagram provided in the lectures is not that great and reading from it can be a major source of error.

Question 6:

The discharge coefficient calculated through the points 6 and 7 showed that it is indirectly proportional with the Reynolds number. An increase in the coefficient was observed with decrease in velocity and Reynolds number.

Run1 Run2 Run3 Run4
Reynolds number, Re 103500 98625 98842