College of Engineering
Department of Civil Engineering and Architecture
Fluid Mechanics
CENG231
Osborne Reynolds Demonstration
Sayed abbas Mohamed 20104762
03
1. Objective:
To reproduce the classical experiments conducted by Professor Osborne Reynolds concerning fluid flow condition.
2. Theory:
Reynolds number, Re is the internationally recognized criterion denoting fluid flow condition. “ Re = 4Q/ πvd ”
Osborn Reynolds determined that values of Re could be assigned to define the transition from laminar to turbulent flow.
3. Apparatus:
-Osborne Reynolds apparatus. -Hydraulics Bench.
-measuring cylinder. -Stopwatch.
-Vegetable Dye. -Thermometer.
4. Procedure:
* Fill the reservoir with dye, position the apparatus on the bench and connect the inlet pipe to the bench feed. Lower the dye injector until it is just above the bell moth inlet. Close the control valve. Open bench inlet valve and slowly fill the head tank to the overflow level, then close the inlet valve .open and close flow control valve to admit water to the flow visualization pipe. Allow the apparatus to stand at least ten minutes before proceeding. Measure the temperature of the water.
* Open the inlet valve slightly until water trickles from the outlet pipe. Fractionally open the control valve and adjust dye control valve until slow flow with dye indication is achieved .measure and note the flow rate.
* Repeat for increasing flow rates by progressively opening the flow control valve. Take a specific measurement of flow rate at the critical condition.
* Repeat the procedure for decreasing flow rates, taking a specific measurement of flow at the critical condition.
5. Results & Calculation:
Water Temp. = 21 C Water density = 998.2 kg /m3
Molecular viscosity = 0.00085 kg /m.s