53:071 Principles of HydraulicsLaboratory Experiment #1

Energy and Hydraulic Grade Lines in Water Pipe Systems

Li-Chuan Chen, Marian Muste, and Larry Weber

Objective

To determine the energy and hydraulic grade lines in a pipeline assembly comprising losses due to friction in conduit as well as head losses due to transitions and fittings.

Principle

Bernoulli’s equation

Lhzg

Vpz

g

Vp 2

22

22

1

21

11

22

EGL 2

HeadEnergy 2

g

Vz

p

HGL Head cPiezometri zp

Apparatus — Standard Pipe

Geometrical characteristics for the pipeline system can be found in the appendices in the handout.

Apparatus — Streamlined Pipe

Geometrical characteristics for the pipeline system can be found in the appendices in the handout.

What are we going to do?

We are going to measure the piezometric heads along a pipeline system.

Procedures

Bleed the pipe system and tubings.Establish stabilized maximum discharge in the system.Measure the datum.Measure and record the pressure head.Measure the head on weir.Measure the water temperature.

Data SheetWater Temp. (F)

Weir Notch Elev. (ft)

W.S. Elev. (ft)

Q (cfs)

Tap # Station (ft)

Eleva-tion (ft)

Piez. Head

(ft Hg)

Piez. Head

(ft H2O)

Pipe Diam.

(ft)

Vel. Head

(ft H2O)

Energy Head

(ft H2O)

Datum

1

2

3

4

Analysis

Compute velocity, piezometric, and energy heads at each pressure tap.Plot the energy and hydraulic grade lines.Discuss the energy budget.Discuss sources of experimental errors.Calculate the horsepower consumed by the system.

Result — Standard Pipe

Further Consideration

Compare the measured values between the pressure taps with computed ones using empirical values found in your hydraulics or fluids textbooks. Explain the discrepancies.

Note — Losses between Tap 5 and 6 through the curved pipe segment should be treated as a lump local loss located at Tap 5.