Flow Measurement - Fluid Mechanics
Name: ********
Class: DME2
Title: Flow Measurement
Date: 11/02/2013
Lecturer: Mr Higgins
Summary:
In this experiment many different meters were used to measure fluid flow rate; the orifice plate, the venture meter, the rota meter and the weigh tank. Each meter works by its ability to alter a certain physical property of the flowing fluid and then allows this alteration to be measured. The measured alterations are linked directly to the flow rate and these measurements are subbed in to adjusted equations to solve for it. Each methods outcome is then analysed, compared against each other. 1. Objectives: * To introduce the student to three typical methods of measuring he flow rate of an incompressible fluid namely; 1- Venturi metre 2- Orifice plate 3- Rotor metre * To compare the accuracy of each device. * To give insight into appropriate industrial application for each device.
2. Theory:
Water enters and first flows through the Venturi metre, then through the Orifice plate and then through the Rotor meter. On leaving the Rotor meter the water flows via a control valve to the weigh-tank of the hydraulic bench. At the inlet and the outlet of each flow measuring device is a connection to the manometer board, this allows the head loss to be determined across each device.
For an incompressible fluid flowing through a pipe the following equations apply:
Continuity, Q=V1A1=V2A2 (1)
Bernoulli’s P1ρg+V122g+z1=P2ρg+V222g+z2 (2)
Venturi
Rewriting Bernoulli’s equation for the experimental apparatus PAρg+VA22g+zA=PBρg+VB22g+zB
Since apparatus is horizontal ZA=ZB therefore, PAρg+VA22g=PBρg+VB22g
Rearranging
VB22g+VA22g=PAρg+PBρg
Since P/ρg is the hydrostatic (pressure) head, h at any given point we can rewrite the above equation as,
VB22g+VA22g=hA-hB (3)
Where hAand hB are read directly from the apparatus.
To solve for velocities, we rearrange equation (1),
VA=VBABAA
Filling into equation
Class: DME2
Title: Flow Measurement
Date: 11/02/2013
Lecturer: Mr Higgins
Summary:
In this experiment many different meters were used to measure fluid flow rate; the orifice plate, the venture meter, the rota meter and the weigh tank. Each meter works by its ability to alter a certain physical property of the flowing fluid and then allows this alteration to be measured. The measured alterations are linked directly to the flow rate and these measurements are subbed in to adjusted equations to solve for it. Each methods outcome is then analysed, compared against each other. 1. Objectives: * To introduce the student to three typical methods of measuring he flow rate of an incompressible fluid namely; 1- Venturi metre 2- Orifice plate 3- Rotor metre * To compare the accuracy of each device. * To give insight into appropriate industrial application for each device.
2. Theory:
Water enters and first flows through the Venturi metre, then through the Orifice plate and then through the Rotor meter. On leaving the Rotor meter the water flows via a control valve to the weigh-tank of the hydraulic bench. At the inlet and the outlet of each flow measuring device is a connection to the manometer board, this allows the head loss to be determined across each device.
For an incompressible fluid flowing through a pipe the following equations apply:
Continuity, Q=V1A1=V2A2 (1)
Bernoulli’s P1ρg+V122g+z1=P2ρg+V222g+z2 (2)
Venturi
Rewriting Bernoulli’s equation for the experimental apparatus PAρg+VA22g+zA=PBρg+VB22g+zB
Since apparatus is horizontal ZA=ZB therefore, PAρg+VA22g=PBρg+VB22g
Rearranging
VB22g+VA22g=PAρg+PBρg
Since P/ρg is the hydrostatic (pressure) head, h at any given point we can rewrite the above equation as,
VB22g+VA22g=hA-hB (3)
Where hAand hB are read directly from the apparatus.
To solve for velocities, we rearrange equation (1),
VA=VBABAA
Filling into equation
Bibliography: 1. CIT laboratory manual: Fluid mechanics-B.S. Massey, Applied mechanics - J.D. Walker, Fluid mechanics - Irfan A. Khan, Mechanical Engineering Science- J. Hannah and M.J. Hiller. 2. Wikipedia – formulas / units confirmation 3. http://fetweb.ju.edu.jo – general information on each measuring meter used.