One is to plot the values of λ and Re on the Moody diagram above. After use, the water is discharged into the drainage tray, passing into the bucket of the measuring apparatus which is carried on a beam. Sample Calculations: Page 8… 1572 Words 7 Pages Fluid Mechanics 3-Aerofoil Lab Report Introduction This report aims to investigate the effect the angle of attack of an aerofoil has on the air flow around it. Students compare their experimental results with Moody and Nickuradse charts. Label and attach each table to this report. To understand how this works we must understand two terms. Install one of the test specimens into the pipe flow rig.
Mounted into the center of the panel are 4 manometer tubes which can be connected by means of flexible rubber tubes to the manometer tappings on either side of the fitting being tested. However, he did not provide adequate data for the variation in f with velocity. Procedure Measure the length of the pipe. Form friction is an energy dissipation that occurs when boundary layer separates and form wakes; for example, flow through valves, fittings, and obstruction such as sudden contraction or enlargement of cross section. Attach a Hoffman clamp to each of the two manometer connecting tubes and close them off.
There is a calibration stand in the lab, which is set up to provide 48. Open the pump inlet valve to its fully open position. Plot graphs for log f against log Re and compare with the Moody diagram. The free end of the beam is designed for use with a hanger carrying masses of a known value. The second portion of the experiment used known….
The variation may be drastic in bends and less variation in straight pipe. This would have affected the fluid flow which might cause the reading on the manometer to fluctuate about the actual value. Last Edited : 30 June 2011 14:00:11. It also makes sure whether the design has to modify or not. The test pipe Test Pipe length is measured in mm. Manometer is filled with H2O make sure that the manometer valves are closely tighten and no presence of air in the manometer. It includes a pipe with a roughened internal bore, and pressure tapping points connected to a manometer.
Figure 1: Minor loss in pipes Yunus, 2011 Sudden expansion or contraction in fluid flow changes the velocity of fluid flow and forms eddies in the fluid. The head loss in a pipe is divided in to two main categories. Compare and discuss the experimental loss coefficients obtained with values in the literature. Add water to or drain water from, using the blue thumb wheel pincher on the drain lines one of the calibration containers if necessary until the water in both containers is at the same level approximately 68 inches on the manometer scale, which has an arbitrary datum plane. This result could have been caused by the error in the viscosity at certain temperatures, leading to an error in the Reynolds number calculated. Connect the bench supply tube to the header tank inflow, run the pump and open the bench valve to allow flow.
Compare and discuss the experimental loss coefficients with values given in the literature. Precision and accuracy… 898 Words 4 Pages Evaluation: There were couple of mistakes that occurred over the span of experiment. Students take readings of temperature from a thermometer supplied and readings of head from the manometer or the pressure meter. Equation 1 can the be used to determine the theoretical head loss if you know the value of f for the pipe. However, the Validyne display unit output is an analog voltage that ranges from only -2 to 2 volts. The equivalent roughness of the pipe is also determined to characterize the average roughness or depth of the irregularities of the surface.
The fluid in this region will have rotation flow because of one fluid layer is flowing over the other. Theoretical analogy shows that the pressure head loss due to minor loss is less compared to major loss. For low velocities, where the flow is laminar, friction loss is caused by viscous shearing between streamlines near the wall of the pipe and the friction factor f is well defined. The change in the values are in appropriate may be because of the change in inner diameter of the pipe network due prolonged use. For this reason, you have also been given the length of pipe between the two measurements. Other than that parallax error could have occurred when taking reading of the manometer and the volume of water in the measuring cylinder. Determine the flow rate by timed collection and measure the temperature of the collected fluid.
The experiment was done using a pipe with a known diameter, and water was pumped in from a tank. Some sources of errors arise in this experiment, which makes deviations of the experimental value of friction factor from the theoretical values. Method To obtain a series of readings of head loss at different flow rates ,through one or more of the smooth bore test pipes. . Pressure tappings in the pipes are connected to the pressure gauge for indication of pressure reading. Turbulence in fluid flow reduces the magnitude of the resistance experienced by the fluid, so less friction will be encountered by the fluid. Results and Calculations 69 O.
For a laminar flow, the Reynolds number could be up to 2000 while for a complete turbulent flow, the Reynolds number could be up to 4000. This was close to the expected critical Reynolds number of 2300. Hoffman Clamp white Measuring Cylinder next to outlet pipe Join the test rig inlet pipe to the hydraulic bench flow connector with the pump turned off. Students set the flow rate, measuring it by timing the collection of water in a measuring vessel included. In turbulent flow, the friction factor is a function of Reynolds Number and relative roughness. Record flow and pressure readings. When the level in the manometers are steady, note the difference in water levels between the two tubes of the manometers.