1. General Information Lab -3 Bernoulli Equation
Worksheet and Spreadsheets due Thursday by 12 noon
Lab Reports due Tuesday by 4.00 pm

2. Objectives
To investigate the validity of Bernoulli’s equation as applied
to a tapering horizontal tube
To determine if the variations in Static pressure head can be predicted by Bernoulli’s equation for tapering horizontal tube

3. Figure1: Test Section and Manometer tubes

4. Theory Bernoulli’s Equation: pressure head or static head = hs
…………………….(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

5. 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

6. Tube diameter (mm) a 25.0 b 13.9 c 11.8 d 10.7 e 10.0 f 25.0 76.08
55.46
15.8
7.4
2.9
5.0 f b c d e a
Tube diameter (mm) a b c d e f

7. Main Objective: Is Bernoulli’s equation validated? Why/ Why not?
Any assumptions violated?
In the Data Sheet: hsm = static head measured and hTm = total head measured
Measurement Points:
Converging
Diverging
Static probe / Piezometer: measures static heads or pressure heads
Pitot Probe: total head

8. 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