Aim:

The aim of this experiment is to determine the head loss coefficient due to sudden expansion in a pipe.

Theory:

The head loss coefficient is defined as the head loss ratio due to a sudden expansion to the fluid flow through the pipe’s dynamic pressure. It is denoted by K and is given by the equation:

K = (h1-h2)/[(V2)/2g]

Where,

h1 = head loss before the expansion,

h2 = the head loss after the expansion, 

V1 = velocity of the fluid before the expansion, 

g = acceleration due to gravity

Apparatus:

1. The sudden expansion of the apparatus
2. Flow measuring device (venturi meter or orifice meter)
3. Manometer
4. Stopwatch
5. Thermometer
6. Water supply
7. Measuring cylinder
8. Scale

Procedure:

1. Set up the sudden expansion apparatus by connecting the pipe with the sudden expansion section to the water supply.
2. Install the flow measuring device (Venturimeter or Orifice meter) to measure the flow rate of the water.
3. Connect the manometer to measure the pressure difference between the two points before and after the sudden expansion.
4. Record the ambient temperature and pressure.
5. Open the valve to allow water to flow through the apparatus.
6. Measure the flow rate using the flow measuring device and the pressure difference using the manometer.
7. Record the time taken for the water to flow through the apparatus.
8. Repeat the experiment for different flow rates by adjusting the valve.
9. Calculate the head loss coefficient (K) using the formula given above.
10. Tabulate the data and plot a graph of K against the Reynolds number (Re).
11. Calculate the average value of K.

Precautions:

1. Ensure the apparatus is properly set up and all connections are tight to prevent leaks.
2. Check the flow measuring device and manometer for accuracy before starting the experiment.
3. Use clean water and ensure that the flow is steady.
4. Record the ambient temperature and pressure accurately.
5. Repeat the experiment several times to obtain reliable results.
6. Ensure that the valve is adjusted carefully to avoid sudden changes in flow rate.

Conclusion:

The head loss coefficient due to sudden expansion in a pipe was determined using the sudden expansion apparatus. The experiment was conducted for different flow rates, and the H coefficient was calculated using the pressure difference and flow rate measurements.

It was observed that the head loss coefficient increases with the Reynolds number. The experiment can be used to design piping systems and to predict the pressure drop across a sudden expansion.