Theory: In this experiment an orifice plate flow-meter is calibrated and the calculated coefficient of discharge, Cd, is compared to the given value in the lab report as well as other published data. The orifice plate flow-meter provides a simple and low cost method for measuring the flow rate in a pipe using the pressure drop measurement across the plate. The orifice plate is a circular plate with a sharp square edge hole in the center inserted in a pipe. When a fluid is allowed to flow inside the pipe, the orifice plate obstructs the flow which results in fluid pressure loss. A schematic diagram of an orifice plate installed in a pipe with flow from left to right is shown in figure 1. The pressure loss is dependent on the orifice diameter, pipe diameter and the flow rate. Hence the flow rate is less than the theoretical flow rate which would occur if there were no losses.

Orifice meterAn orifice meter is a differential pressure flow meter which reduces the flow area using an orifice plate. An orifice is a flat plate with a centrally drilled hole machined to a sharp edge. The orifice plate is inserted between two flanges perpendicularly to the flow, so that the flow passes through the hole with the sharp edge of the orifice pointing to the upstream. The relationship between flow rate and pressure drop can be determined using Bernoullis equation as:

whereQactual= Actual = volumetric flow rate m/sCd=Discharge co-efficient of orifice meterAo= is the orifice cross sectional areaA1 =area at the inlet side in m2A2 =area at the throat side in m2P =Differential pressure head of liquid in mg =Acceleration due to gravity (9.81 m/s2) =Density of fluidProducers:1. The device is composed of tank filled with distilled water and reservoir is composed of pump and control panel.2. Before start the device all the valves open to get rid of the bubbles and then close all valves except valve leading to the orifice.3. Turn the pump on and adjust the flow rate to a constant level using the valve on the tub. To adjust the flow rate for the rest of the lab, use the valve located on the orifice meter. This will avoid introducing air into the system.4. Open source of water and pray the water valve to the tank being by the rising tube.5. Open the valve control (valve Rota meter) on the flow of water to the cylinder Rota meter.6. Note manometer filled with water by the pump determine the level of change in height or determine the(h1,h2) a difference (h)7. Repeat several steps to get several reading ().8. After the end of the experiment all the valves closed

Calculation:V2=1. Qact = 600 **= 0.00016V2= =0.645Qideal = A2*V2A= = = 0.00126Qideal = A2*V2 = 0.00126*0.645 = 0.000813Cd = = = 0.1972. Qact = 800 **= 0.00022V2= =0.96

Qideal = A2*V2A= = = 0.00126Qideal = A2*V2 = 0.00126*0.96 = 0.00121Cd = = = 0.182

3. Qact = 1000 **= 0.00027V2= =1.128

Qideal = A2*V2A= = = 0.00126Qideal = A2*V2 = 0.00126*1.128 = 0.00142Cd = = = 0.19

4-Qact = 1200 **= 0.00033V2= =1.325

Qideal = A2*V2A= = = 0.00126

Qideal = A2*V2 = 0.00126*1.325 = 0.00167Cd = = = 0.1985. Qact = 1400 **= 0.00038V2= =1.554

Qideal = A2*V2A= = = 0.00126

Qideal = A2*V2 = 0.00126*1.554 = 0.00196Cd = = = 0.194CdV2

Qideal

hmhmmQact

Qact

0.1970.6450.0008130.019190.00016600

0.1820.960.001210.042420.00022800

0.191.1280.001420.058580.000271000

0.1981.3250.001670.08800.000331200

0.1941.5540.001960.111100.000381400

Discussion:1-In engineering practice, it is rarely possible to measure the rate of flow of a fluid by a direct volumetric or gravimetric determination. Frequently, the metering is accomplished by the observation of some measurable quantity related to the rate of discharge. Orifices, nozzles, Pitot and orifice meter tubes produce a differential pressure related to the flow velocity. The differential pressure can be measured with a manometer, pressure gage, or pressure sensor. Pressure sensors are widely used because they provide a voltage output that can be monitored easily by computer.

2- After an experience we noticed several errors in the readings due to lack of bubbles out completely. In order to correct the piece must take out all the bubbles from the pipeline Rota meter by pressure on the tube and then we pressing the pump to see the difference between (h1, h2)But if orifice meter diagonally may differ from the usual orifice meter and the piece because the angle changed.3- To calculate theoretical discharge rate through orifice meter (Qt) and to measure actual flow rate (Qa) through orifice meter.To determine the value of coefficient of discharge Cd.

4- Also, there may be a slight difference between Qact and Qideal teams called this rate errors

An error rate as a result of the mistakes of the process which may be the result of not controlling the read QR or not to calculate the exact time when the cylinder with water movement. And took many different read and QR's and get different results.

Diagram: