Lab -3 Bernoulli Equation

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Lab -3 Bernoulli Equation

• General Information
• Worksheet and Spreadsheets due Thursday by 12
  noon
• Lab Reports due Tuesday by 4.00 pm

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• Objectives
• To investigate the validity of Bernoullis
  equation as applied
• to a tapering horizontal tube
• To determine if the variations in Static
  pressure head can be predicted by Bernoullis
  equation for tapering horizontal tube

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Figure1 Test Section and Manometer tubes
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Theory Bernoullis Equation
.(1)
If horizontal tube leveled correctly, then z1
z2, and equation 1 is then simplified to
..(2)

pressure head or static head hs
velocity head hv
Total head hT hs hv
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Assumptions

• Bernoulli made some assumptions for his equation
  to work
• Inviscid (no shear stress)
• Flow is steady
• Points 1 and 2 which you are comparing are in
  the same streamline
• Density of the fluid is constant
• System is not accelerating

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76.08
55.46
15.8
7.4
2.9
5.0
f
b
c
d
e
a
Tube diameter (mm) a
25.0 b
13.9 c 11.8
d 10.7
e 10.0 f
25.0
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Main Objective Is Bernoullis equation
validated? Why/ Why not?  
Any assumptions violated?   In the Data
Sheet hsm static head measured and hTm total
head measured   Measurement Points
Static probe / Piezometer measures static heads
or pressure heads Pitot Probe total
head
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Analysis

• Determine three flow rates ( High / Medium / Low)
• Calculate the velocity head at each cross section
• Calculate the best estimate of the total head hT
  in the tube
• Predict the variation of static pressure head hSc
  along the length of the tube - Compare measured
  static head to calculated static head value
• Graph values of hT htm hSm hsc hvc as a
  function of position along the tube
• Discuss the converging and diverging section and
  how the values change within them
• Discuss the effect of change in flow rate on
  observations
• Comment on validity of B.Eq. for convergent and
  divergent flows