FLUID FLOW METER

GROUP MEMBERS

NAME MATRIC NUMBER

AHMAD FIKRI B AHMAD SUPIAN CD140150AHMAD SYAKIR B MOHD ZAINUDDIN CD140149

FATIN AMIRA BINTI REBBUAN CD140123

HILDA FAZRINA BINTI MARWAN CD140031

MOHAMAD FAIZ B MOHD ZIN CD140068

INTRODUCTION

THEORY

Using the Bernoulli’s equation

ORIFICE PLATE

• A plate with a machined hole in the center.• The flow rate is determined by measuring the

pressure drop as the flow passes through the plate. • for orifice meter with D1 and D2 being diameters of

the pipe and the orifice hole, respectively.• The frictional losses in the orifice meter are much

larger than in the venturi meter and a typical value of the discharge coefficient Cd.

• Precise value Cd should be determined experimentally.

• The pressure is measured by manometer.• So we solving it by bernouli equation.

VENTURI METER

• A venturi meter is a tube of non-constant diameter

• To minimize disturbances to the flow, the edges of the venturi meter have the same diameter as the pipe into which the meter

is inserted. • Variation of the tube diameter leads to

variation of the fluid pressure inside the meter.

• Therefore, we can determine the flow rate by measuring pressures p1 and p2 at

these locations and substituting them into the Bernoulli equation.

• The kv is constant in calculation.

PITOT TUBE

A Pitot or impact tube makes use of the difference between the static and kinetic pressures at a single

point. A similar device which is in effect a multiple pitot tube, averages the flow profile

The principle is based on the Bernoulli Equation where each term of the equation can be

interpreted as pressure.The pitot tube is a simple and convenient instrument

to measure the difference between static, total and dynamic pressure (or head).

So the discharge coefficient for pitot tube is same as venture meter

The kp is constant.

OBSERVATION

BEFORE TESTING•Level the apparatus on the

hydraulic bench.•Open the discharge valve (2) of the test set. Open the vent valve

(1) on manometer top manifold and attach the hand air pump.

• Open the measuring tank discharge valve and closed the

bench supply valve.

AFTER THE TEST•Switch on the hydraulic bench pump and open the bench supply valve for maximum flow rate until air bubbles are completely removed from the test set.

• Set the manometer reading (3) to 22 l/min by control the bench supply valve.• Close the vent valve and pump air into the manometer head manifold until the manometer level in tube 1 give a reading of 40 cm.

• Close the measuring tank discharge valve and record the time to fill in 5 liter of water into the measuring tank.• Record the water manometer level for orifice meter, venture meter and pitot tube.

•Open the measuring discharge valve to flow back the water into a water tank.• Repeat the step for flow rate 20,18,16,14,12,10 and 8 l/min.

Observation of the experiment conducted

• When flow rate increase, the time is decrease which cause the actual flow rate

slightly less than theorical flow rate.•For orifice meter, the flow rate increase,

the inlet and outlet also increase.•For venture meter, the flow rate increase,

the inlet increase, the outlet decrease.•For pitot tube, the flow rate increase, the

inlet and outlet decrease.

CALCULATION & RESULT

Table 6.3 Calculation of Discharge Coefficient for Venturi Meter, Cv

Table 6.4 Calculation of Discharge Coefficient for Pitot Tube, Cp

DISCUSSION

A) From the graph, Explain the change of discharge coefficient, Cd due to flow rate Q.

From the graph we can see that the value of Co, Cu and Cp is fluctuated. This can be happened due to errors that occurs when conducting the experiment

and can cause unaccurate value. The error that happen is Parallax Error when record the reading of the water level for rotameter and manometer. To avoid it, student eyes must be parallel with the water level of the indicator when

reading the value

B) Describe why the different of the discharge coefficient occur between the orifice, venturi meter and pitot tube.

From the result we can see that the value of discharge coefficient is different in each apparatus which is orifice meter, venturi meter and pitot tube because

the shape of the devices. Other than that the velocity and pressure in each device can make the value of discharge coefficient become different. From the table we can see that venturi meter has the highest value of discharge coefficient while in pitot tube the value of discharge coefficient is lowest.

This because the diameter of inlet and outlet is the same.

CONCLUSION &

RECOMMENDATION

In conclusion, students are able to understand about fluid flow meter and gain knowledge about the process and how its work.

Students are able to determine the value of discharge coefficient of an orifice meter, venturi meter and pitot tube.

The problem we faced during the experiment is when record the reading the value of height of fluid in manometer because

the indicator keep moving up and down. For improvement I suggest a better indicator that make it easier to read such as

using digital reading meter. However this experiment was successful.

REFERENCE

1. https://www.grc.nasa.gov/www/k-12/airplane/pitot.html2. Yunus A. Cengel, john M. Cimbala , Fluid Mechanics-

Fundemantals and Application (2006), McGraw Hill.3. http://

www.engineeringtoolbox.com/pitot-tubes-d_612.html4.http://webcache.googleusercontent.com/search?q=cache:k1InDUUjxF0J:www2.emersonprocess.com/siteadmincenter/pm%2520daniel%2520documents/fundamentals-of-orifice-measurement-techwpaper.pdf+&

cd=4&hl=en&ct=clnk5. http://beta.merriam-webster.com/dictionary/venturi

6. Robert A. Granger (1998), Experiments in Fluid Mechanics, HRW, Inc.