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Masangkay, RamonNoche, SandyOrdillano, Graziela
Pacia, Rose Mardie
Mechanical energy lossesdue to straight and fittings
in a viscous pipe flowsystem
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Objectives:
To measure the energy lossesthrough the straight pipe
andfittings in a pipe flow system.
To determine the relation of energylosses to the volumetric flow
rate ina pipe flow system from actual data.
To measure the performance of thefluid flow system in the lab
bycomparing the design calculationswith the experimental data.
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Introduction
Pipe flows belong to a broader classof flows, called internal
flows, wherethe fluid is completely bounded by
solid surfaces.
The nature of pipe flow isdependent on whether the flow is
turbulent or laminar and this is due tothe differences in the
nature of theshear stress in laminar and turbulentflows.
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Consequently, the physicalproperties of the shear stress
isdifferent for laminar than for turbulent
flow. For laminar flow, it isindependent of density, thus,
leavingthe viscosity as the very importantproperty; while for
turbulent flow,density is an important property.
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When a fluid flows through a pipe,there is a loss of pressure in
the fluid,because energy is required to overcomethe viscous or
frictional forces exerted
by the walls of the pipe on the movingfluid. This can be seen in
theMechanicalenergy balance equation:
PE + KE+ P + F =Ws
- P = F
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In addition to the energy lost due tofrictional forces, the flow
also losesenergy (or pressure) as it goes throughfittings, such as
valves, elbows,
contractions and expansions.
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Equipments/ Materials:
-Fluid flow unit
-U-tube manometer
-Water hose
-Water
-Ruler
-Pail
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Procedure
Start Up
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Experimental Procedure
Close otherisolatingvalves
Set the openingof the entryvalve to thedesignated
degree
Measure the steadystate static
pressures using theU-tube manometer
Locate thedesignatedhorizontal
run
Repeat steps 2 and3 for a different
volumetric flow rate
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Shut Down
Open allisolatingvalves
Slowly reducethe flow rateby reducing
the degree ofopening of the
entry valve
Switch off thepump
Open thedrain valve
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Data and Results:
Rm F26.67 2.61
25.67 2.52
23 2.25
22 2.16
20 1.96
18.67 1.83
17.67 1.73
16 1.57
15 1.47
14.33 1.40
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Sample Calculations:
Experimental
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Theoretical:
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Flow rate (gal/hr) Velocity( m/s) f F
800 1.715 0.0216 2.34
750 1.608 0.022 2.14
700 1.501 0.0223 1.89
650 1.394 0.0227 1.66
600 1.286 0.0231 1.44
550 1.179 0.0236 1.236
500 1.072 0.0241 1.044
450 0.965 0.0248 0.870
400 0.858 0.0255 0.707
350 0.750 0.0263 0.557
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References:
Munson, B. R., Young, D.F., and Okiishi, T.H., Fundamentals of
Fluid Mechanics, 3rded., John Wiley and Sons, Inc., 1998.
http://www.eng.fsu.edu/~alvi/EML4304L/webpage/
http://www.eng.fsu.edu/~alvi/EML4304L/webpage/experiment_5.htmhttp://www.eng.fsu.edu/~alvi/EML4304L/webpage/experiment_5.htm
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ThankYou!
