Venturi
INTRODUCTION
A venturi tube is a tube with a constricted throat that increases velocity and decrease pressure while an Orifice plate is a device which measures the rate of fluid flow. The Venturi Tube and Orifice Plate are basically used to determine flow rate in piping systems. Both of them used the same principle which is Bernoulli’s Equation. Based on Bernoulli’s Equation which says that there is a relationship between the pressure of the fluid and velocity of the fluid. In a flow metering device, the downstream pressure before an obstruction will be higher than the upstream pressure after. The Venturi Tube has less head loss than Orifice Plate due to its streamlined design.
Orifice Plate
Venturi Tube
The objectives of this experiment are ; * To determine the coefficient of discharge of Venturi tube. * To determine the coefficient of discharge of Orifice plate.
APPARATUS
Ball cocks for shutting off part sections
Back wall
Annular chambers with pressure tapping nipple
Tubular steel frame with suction pads
Double pressure gauge
Inlet (concealed)
Diagram 1
Adjustable measurement system
PROCEDURE
Part A : Flow through Venturi Tube 1. The inlet and throat diameters of Venturi tube were recorded. 2. The Venturi tube into section 6 was fixed as shown in figure 1. 3. All valves were closed except those that will let the water flows from the tank to section Ventori tube and return back to the tank. 4. The manometer hoses to the pressure tapping points of the Venturi tube were connected. 5. The pump was switched on. Air bubbles was removed from the apparatus. 6. The valves on the left side of the Venturi tube were adjusted to a certain point. 7. The values of h1 and h2 were measured and recorded. 8. The actual volume flow rate (Qactual) were measured and recorded. 9. Step 6 to 8 for 5 values of Qactual were repeated.
Part B : Flow through Orifice Plate 1. The inlet and throat
A venturi tube is a tube with a constricted throat that increases velocity and decrease pressure while an Orifice plate is a device which measures the rate of fluid flow. The Venturi Tube and Orifice Plate are basically used to determine flow rate in piping systems. Both of them used the same principle which is Bernoulli’s Equation. Based on Bernoulli’s Equation which says that there is a relationship between the pressure of the fluid and velocity of the fluid. In a flow metering device, the downstream pressure before an obstruction will be higher than the upstream pressure after. The Venturi Tube has less head loss than Orifice Plate due to its streamlined design.
Orifice Plate
Venturi Tube
The objectives of this experiment are ; * To determine the coefficient of discharge of Venturi tube. * To determine the coefficient of discharge of Orifice plate.
APPARATUS
Ball cocks for shutting off part sections
Back wall
Annular chambers with pressure tapping nipple
Tubular steel frame with suction pads
Double pressure gauge
Inlet (concealed)
Diagram 1
Adjustable measurement system
PROCEDURE
Part A : Flow through Venturi Tube 1. The inlet and throat diameters of Venturi tube were recorded. 2. The Venturi tube into section 6 was fixed as shown in figure 1. 3. All valves were closed except those that will let the water flows from the tank to section Ventori tube and return back to the tank. 4. The manometer hoses to the pressure tapping points of the Venturi tube were connected. 5. The pump was switched on. Air bubbles was removed from the apparatus. 6. The valves on the left side of the Venturi tube were adjusted to a certain point. 7. The values of h1 and h2 were measured and recorded. 8. The actual volume flow rate (Qactual) were measured and recorded. 9. Step 6 to 8 for 5 values of Qactual were repeated.
Part B : Flow through Orifice Plate 1. The inlet and throat
References: * http://www.engineeringtoolbox.com/orifice-nozzle-venturi-d_590.html * http://navalfacilities.tpub.com/mo221/mo2210077.html * Fluid Mechanics Fundamentals and Applications, Yunus A.Cengel and John M.Cimbala