TABLE OF CONTENTS

CONTENTSPAGE NO.

1.0 ABSTRACT3

2.0 INTRODUCTION3

3.0 OBJECTIVE4

4.0 THEORY4-9

5.0 APPARATUS9

6.0 EXPERIMENTAL PROCEDURES10-11

7.0 RESULTS12-19

8.0 DISCUSSION20

9.0 CONCLUSION20

10.0 RECOMMENDATIONS21

11.0 REFERENCES21

12.0 APPENDICES22-23

1.0 ABSTRACTOn the last 2nd APRIL 2014, we have succeeded perform the experiment of Flow Meter Demonstration by using the apparatus of Flow meter Measurement (Model:FM101). The objective of this experiment is to obtain the flow rate measurement by utilizing three basic types of flow measuring techniques; rotameter, venture meter, and orifice meter and also to investigate the loss coefficient of fluid through 90 degree below. This experiment is divided into two parts; Experiment 1 is demonstration of the operation and characteristics of three different basic types of flowmeter, Experiment 2 is determination of the loss coefficient when fluid flows through a 90 degree elbow. From the first part, the flow rate measurement for three basic types of flow measuring techniques are calculated using the formula of Bernoullis equation.

The loss coefficient when fluid flows through a 90 degree elbow is calculated in part 2. From the data collected, a graph of Piezometer versus velocity head is plotted. K value is obtained from the gradient of the graph which is 0.576.

2.0 INTRODUCTIONSOLTEQ Flowmeter Measurement Apparatus (Model: FM101) apparatus has been designed to introduce students to the operating characteristics of various types of flowmeter and also to operate together with a basic hydraulic bench or any water supply. It is to familiarize the students with such typical methods of flow measurement of an incompressible fluid. The unit consists of a venture meter, a rotameter and an orifice plate, which installed in series configuration in order to permit direct comparison. It is able to demonstrate the flow measurement comparison by using the three different basic types of flowmeter. To compare again the flow measurement of the hydraulic bench, the flow comparison can be further used which can be either by Volumetric Method or Gravimeteric, this depending on the types of hydraulic used.The flow apparatus include a 90 degree elbow with pressure tappings, so that the head loss characteristics of each flow can be measured. The tappings are connected to an eight-tube piezometer bank that incorporating a manifold with air bleed valve. This allow the students to calculate the total head loss and loss coefficient when fluid flows through these devices.The Flowmeter Measurement Apparatus allows following range of experiment to be carried out :a) Direct comparison of flow measurement using venture, orifice, rotemeter and bench.b) Determination of total head loss and coefficient of fluid flow through a 90 degree elbow.c) Comparison of pressure drop against each device.

3.0 OBJECTIVESThere are two objectives in this experiment : To obtain the flow rate measurement by utilizing three basic types of flow measuring techniques; rotameter, venture meter and orifice meter. To investigate the loss coefficient of fluid through 90 degree elbow.

4.0 THEORY1) RotameterA rotameter is a device that measures the flow rate of liquid or gas in a closed tube. It is a flow meter in which a rotating free float is the indicating element. Rotameters must always be used with a calibration chart to convert observed scale readings to flow rate. Floats are constructed of metals of various densities, glass or plastic. They also may have various shapes and proportions for different applications. It consists of a transparent tapered vertical tube through which fluid flows upward. The float rests on a stop at the bottom end when there is no flow of fluid. But then as flow commences, the float rises until upward and weight balanced the buoyancy forces. Basically, the float will rises only a short distance if the flow rate is small, and vice versa. The function of flow rate is the point of equilibrium. With a well-calibrated market glass tube, the level of the float becomes a direct measure of flow rate.

Figure 1 : The Rotameter2) Venturi MeterThe venturi meter is designed to recover most of pressure drop. To prevent separation in the boundary layer, and minimized the friction, the angle of downstream cone is sufficiently small. But then friction can not be completely eliminate. That is why there is always a pressure drop across the venture meter. However, in a well-designed meter, about 90% of the entrance is recovered.The Venturi meter consists of a venture tube and a suitable diferential pressure gauge. The Venturi effect is the reduction in fluid pressure that results when a fluid flows through a constricted section of pipe.Its tube has a converging portion, a throat and a diverging portion. The converging portion helps to increase the fluid velocity and lower the static pressure. A pressure difference between inlet and throat is thus developed, which pressure difference is correlated with the rate of discharge. The diverging cone serves to change the area of the stream back to the entrance area and convert velocity heat into a pressure head.

Figure 2 : Venturi Meter

Assume incompressible flow and no frictional losses, from Bernoullis equation..(1)Use of the continuity Equation Q=A1V1=A2V2 equation (1) becomes

Ideal

However, in the case of real fluid flow, the flow rate will be expected to be less than that given by equation (2) because of the frictional effects and consequent head loss between inlet and throat. In metering practice, this on-ideality is accounted by insertion of an experimentally determined coefficient, Cd that is termed as the coefficient of discharge. With Z1-Z2 in this apparatus, equation (3) becomes

Actual : Hence,

Where, Cd = Coefficient of discharge (0.98)D2 = Throat diameter = 16mmD1 = Inlet diameter = 26mmAt = Throat area = 2.011 x A = Inlet area = 5.309 x g = 9.81 m/p = Density of water = 1000kg/P1 = Inlet pressure (Pa)P2 = Throat pressure (Pa)

3) Orifice MeterThe orifice meter consists of a flat orifice plate with a circular hole drilled in it. There is a pressure tap upstream from the orifice plate and another just stream. The orifice is use as a metering device in pipeline which consists of a concentric square-edged circular hole in thin plate, which is clamped between the flanges of the pipe.

Figure 3 : Orifice MeterPressure connections are made at holes in the pipe walls on both side of the orifice plate which for attaching separate pressure gauge. The downstream pressure tap is placed at the minimum pressure position, which is assumed to be at the vena contracta. The centre of the inlet pressure tap is located between one-half and two pipe diemeter is employed. Equation (4) for the venturi meter can also be applied to the orifice meter :Actual : The coefficient of discharge, Cd in the case of the orifice meter will be different from that the case of a venture meter.

Where,Cd = Coefficient of discharge (0.63)D2 = Throat diameter = 16mmD1 = Inlet diameter = 26mmAt = Orifice area = 2.011 x A = Orifice upstream area = 5.309 x (h7-h8) = Pressure difference across orifice (m)4) 90 Degree Elbow

Figure 4 : Piezometric head along a pipeline

The figure above shows fluid flowing in a pipeline where there is some pipe fitting such as bend or valve, and change in pipe diameter, which included the figure is the variation of piezometric along the pipe run, as would be shown by numerous pressure tappings at the pipe wall. By introducing the velocity heads in the upstream and downstream runs in the pipe, total head loss H, can be determined in which :H = h + - Experimental values for energy losses are usually expressed in terms of a dimensionless loss coefficient K, whereK = or Depending on the context.

Figue 5 : 90 degree elbowThe value of the loss coefficient K is dependent on the ratio of the bend radius, R to the pipe inside diameter D. as this ratio increase, the value of K will fall and vice versa.H = K x Where, K = Coefficient of lossesV = Velocity of flowg = 9.81 m/

4.1 SPECIFICATION OF DIMENSIONi)

Tapping A = 26mmTapping B = 21.6mmTapping C = 16 mmTapping D = 20mmTapping E = 22mmTapping F = 26mm

ii)

Orifice upstream diameter (G) = 26mmOrifice diameter (H) = 16mm

5.0 APPARATUSSOLTEQ Flowmeter Measurement Apparatus (Model FM101)

6.0 PROCEDURES6.1 General Started up the apparatus :1. The flow control valve of the hydraulic bench is fully closed and while the discharge valve is fully open.2. The discharge hose is ensured properly directed to the volumetric tank of fiberglass before stated up the system. Volumetric tank drain valve is left opened to allow discharge back into sump tank.3. Once step (2) is confirmed, the pump supply is started up from hydraulic bench. The bench valve is opened slowly.4. Then proceed to fully open the flow control valve. When the flow in the pipe is steady, and there is no trapped bubble, the bench valve is started to close and reduced the flow to the maximum measurable flow rate.5. At the point of water level in the manometer board is too high, the flow is slowly reduced by controlling the discharge valve of apparatus.

6.2 Demonstration of the operation and characteristics of three different basic types of flowmeter.1. The apparatus is placed on bench, then the inlet pipe is connected to bench supply and while the outlet pipe into the volumetric tank.2. The pump supply is started up from hydraulic bench with the bench valve fully closed and discharge valve is fully opened.3. The bench valve is slowly opened until it is fully opened.4. When the flow in the pipe is steady, and there is no trapped bubble, the bench valve is started to close to reduce the flow to the maximum measureable flow rate. 5. Then by using the air bleed screw, water level is adjusted in the manometer board. The maximum readings on manometer is retained with the maximum measureable flow rate.6. Readings on manometers (A-J) is noted, followed by rotameter and measured flow rate. 7. Step 6 is repeated for different flow rates. The flow rate can be adjusted by utilizing both bench valve and discharge valve.8. To demonstrate similar flow rates at different system static pressure, adjust bench and flow control valve together. Adjusting manometer levels as required. 6.3 Determination of the loss coefficient when fluid flows through 90 degree elbow.1. Apparatus is placed on the bench, inlet pipe is connected to bench supply and outlet pipe to volumetric tank.2. With the bench valve is fully closed, and the discharge valve fully opened, the pump supply is started up from hydraulic bench.3. The bench valve is slowly opened until fully opened.4. When the flow in the pipe is steady, and there is no tapped bubble, the bench valve is started to close, to reduce the water level in the manometer board.5. By using the air bleed screw, the water in level in the manometer board is adjusted.6. Readings on manometer (I-J) is noted and measured the flow rate.7. Step 6 is repeated for different flow rates. The flow rates can be adjusted by utilizing both bench valve and discharge valve.8. The table is completed.9. A graph of H against for 90 degree elbow is plotted to determine the coefficient of losses.

General Shut-Down Procedures1. The water supply valve and venture discharge valve is closed.2. Water supply pump is turned off.3. Water is drained off from the unit when not in use.

20

7.0 RESULTS AND CALCULATION7.1 Demonstration of the operation and characteristic of three different basic types of flowmeter Manometer reading (mm)Rotameter (l/min)Vol (l)Time (min)Flowrate, Q (l/min)Flowrate calculated using the Bernoulli's Equation (l/min)

ABCDEFGH IJVenturi Orifice

257256250254256257256244249248531.172.563.583.99

2752702432592642692672032272261030.525.7710.129.20

3002892372652742822811321891861530.329.3814.2014.04

349321215284300313312501501452030.2213.6420.7218.62

Determination of the loss coefficient when fluid flows through a 90 degree elbow

Volume(L)Time(sec)Flowrate,Q(l/min)Differential Piezometer Head, h' (mm)VV2/2g

(m/s)(mm)

Elbow (hI-hJ)

3622.9010.090.42

3315.8110.181.69

3199.4740.304.50

31412.8650.408.28

Demonstration of the operation and characteristic of three different basic types of flowmeter

VENTURI FLOW RATEFor rotameter flow rate = 5 l/min

For rotameter flow rate = 10 l/min

For rotameter flow rate = 15 l/min

For rotameter flow rate = 20 l/min

ORIFICE FLOW RATEFor rotameter flow rate = 5 l/min

For rotameter flow rate = 10 l/min

For rotameter flow rate= 15l/min

For rotameter flow rate = 20 l/min

Determination of the loss coefficient when fluid flows through a 90 degree elbow

1= 2.90 l/min = 4.83 X 10-5 m3/sVelocity of flow in the pipe (Diameter = 26 mm)

= 0.09 m/s

2 = 5.81 l/min = 9.68 X 10-5 m3/sVelocity of flow in the pipe (Diameter = 26 mm)

= 0.18 m/s

3= 9.47 l/min = 1.578 X 10-4 m3/sVelocity of flow in the pipe (Diameter = 26 mm)

= 0.30 m/s

4= 12.86 l/min = 2.14 X 10-4 m3/sVelocity of flow in the pipe (Diameter = 26 mm)

= 0.40 m/s

K = Slope = K = 0.5746

8.0 DISCUSSIONSAll the experiment need to perform start-up procedure first before doing the following experiments. The start-up procedure was to make sure that the entire component is in proper condition to avoid any mistakes. Experiment 1 is conducted to demonstrate the operation and characteristics of three different basic types of flowmeter. Fluid flows produce highest flow rate in venturi meter. Flow rate calculated here is called Qideal due to the equation that is derived from the Bernoullis equation which is for ideal flow and does not involve the effects of frictional forces. The converging cone of a venture meter, which fluid enters, typically has a cone angle of 15-20 degree. This cone which is on the inlet side of the meter converges to the throat diameter, which where the area the flow is at its minimum, thus the velocity here is at its maximum. Meanwhile, orifice is the simplest among the three different types of basic flowmeters, due to its abrupt decrease in flow area, and abrupt transition back to fill pipe diameter. Orifice has the greatest frictional pressure loss. Orifice is less accurate as we cannot use the exact location and diameter of the point of the maximum convergence in calculations. For rotameter, its float response to flowrate changes is linear and it has low pressure drop. Fluid flow raises a float in a tapered tube, which increasing the area for the passage of fliud.Experiment 2 is about determination of the loss coefficient when fluid flows through a 90 degree elbow. From the data collected, a graph of Piezometer versus velocity head is plotted. From the graph, K value obtained is 0.5746. k is the dimensionless loss coefficient that proportional to the velocity head of the fluid as it flows around an elbow. The value of K is independent on the ratio of the bend radius, to the pipe inside diameter. As this ratio increases, the value of K will fall and vice versa. In general, it is found that coefficient (K) decreases as the fittings increased.

9.0 CONCLUSIONSThe flowrate measurement by three basic types of flow measuring techniques; rotameter, venturi meter, and orifice meter are determined and from the results can be conclude that fluid flows produce highest flow rate in venturi meter compared to rotameter and orifice. From the loss coefficient calculated which is 0.5746 shows that value of K decreased as the fitting size increased.

10.0 RECOMMENDATIONSThroughout the experiment, in order to reduce the potential of inaccuracy in obtaining measured data, a few recommendations and precautions must be considered during performing the experiment. First of all, safety glasses with side shields should be worn during the experiment running. Since the tap water is used, students must be careful of the outlet hose position and the position of the bench also the flow control valves when starting the pump. This is because it is easy for the outlet hose to spray water and possible to blow off the pressure tap hoses and spray water all over. Besides, each readings of the recorded data should be taken at least two or three times, then take the average in order to get more precise and accurate readings. Next, the apparatus should not be exposed to any shock and stresses. Students also must run the experiment after fully understand the unit and procedures to avoid any misusing the apparatus that may lead to error in the experimental results

11.0 REFERENCESThe Bernoulli Equation. (n.d.). Retrieved from http://www.efm.leeds.ac.uk/CIVE/CIVE1400/Section3/bernoulli.htmOrifice, Nozzle and Venturi Flow Rate Meters. (n.d.). Retrieved from http://www.engineeringtoolbox.com/orifice-nozzle-venturi-d_590.htmlPressure drop in pipe fittings and valves | equivalent length and resistance coefficient. (n.d.). Retrieved from http://www.katmarsoftware.com/articles/pipe-fitting-pressure-drop.htmRotameters. (n.d.). Retrieved from http://www.omega.com/prodinfo/rotameters.html

12.0 APPENDIX

SOLTEQ Flowmeter Measurement Apparatus (Model: FM101)