Apparatus required :

CCL₄ manometer, H_g manometer.

Procedure :

1. Keep the valve leading to the smooth pipe open and valves leading to other lines closed.
2. Keep the bypass valve completely open and the main valve completely closed. Switch on the pump.
3. Connect a CCL₄ manometer, to the pressure taps across the smooth pipe. Ensure that no air bubbles present and height in both the limbs of manometer are the same.
4. Set a flow rate of water through the pipe by opening the main valve and throttling the bypass valve suitably using the rotameter.
5. Note down the rotameter reading and manometer reading after a steady state is attained.
6. Increase the flow rate of water by opening the main valve and throttling the bypass valve suitably and repeat step 4 and 5.
7. Use mercury manometer for higher flow rates.
8. Take eight readings with CCL₄ manometer as well as with H_g manometer.

Data :

Diameter of the pipe= D =        m
Length of the pipe= L =        m
Density of water ==        kg/m³
Viscosity of water = =cp=       kg/ms
Density of CCl₄ = 1600 kg/m³

Density of Hg = 13600 kg/m³

Observations :

Calculations :

1. ∆Hm is cm of manometric fluid
2. Volumetric flow rate, Q = m³/s
3. Pressure drop in m of water
4. Cross sectional area of the pipe A =
5. Average velocity through the pipe = V=Q/A = m/s
6. Reynolds number = NRe ==
7. Friction factor f is calculated using f Blasius equation:
8. Friction factor
9. Nicurdse’s correlation:

To verify Nicurdse’s correlation:

on a semi log graph :

• Find the slope and intercept.
  
• Compare with Nicurdse ’s correlation.
  
• Discuss on effect of Reynolds number on friction factor.