Pipe Friction

ME313L Fluid Mechanic Lab Manual (DRAFT)

Pipe Friction Experiment
Object: The friction loss in a small-bore horizontal pipe is to be determined over a wide range of Reynolds number. Both laminar and turbulent flow regimes are to be studied. Equipment: Air valve

Water manometer

Mercury U-tube

Isolating tap meter From water supply Needle valve

Test tube Figure 1 Pipe friction apparatus A. Laminar Flow The laminar pipe friction apparatus is shown above. It consists of a water loop. The volumetric hydraulics bench serves as the water supply reservoir. Water is pumped up to a header tank through a ball valve A so that a constant head is provided for the laminar flow experiment. The constant head is maintained by means of an overflow tube in the header tank. The water then flows from the outlet pipe of the header tank to the pipe friction test bench through another ball value B. It then flows through a 3 mm

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ME313L Fluid Mechanic Lab Manual (DRAFT) diameter pipe 524 mm long. Pressure taps are located at both ends of the pipe. The pressure drop is measured by a water manometer attached to each pressure tap. The water flow rate is controlled by a needle valve. The water is then collected in a calibrated beaker and timed for flow rate and the returned to the hydraulics bench. B. Turbulent Flow The equipment for turbulent flow measurements is the same as that for laminar flow measurements with two exceptions. 1) The flow from the hydraulics bench goes directly to the pipe friction test bench though a ball valve C and the header tank (and valves A and B) is bypassed . 2) The pressure drop across the test pipe is measured by a mercury Utube manometer. The turbulent flow water loop is shown below. Procedure: A. Laminar Flow 1) Ensure that the valve on the hydraulics bench is closed and the pump is turned off. 2) Open ball valves A and B and close ball valve C. The will cause the water to be sent to the header tank 3) Turn on the pump in the hydraulics