CE 3105 - Mechanics of Fluids Laboratory¶

Laboratory 4 - Friction Losses in a Pipe¶

Low Flow Rates

Connect the output of the hydraulic bench to the header tank, and the output of the header tank to the inlet of the test pipe
Turn on the hydraulic bench pipe and adjust its supply valve carefully to ensure a steady ow without over owing the header tank
Partly open the needle valve of the test pipe at the downstream to pass the water through it
Bleed the trapped air as necessary using the bleed pipe and connect the hand-held pressure meter
Record the pressure meter readings (you may need to use the manomeeters if the $\Delta p$ is too small for the instrument to detect.
Measure the discharge by collecting a known amount of water in a given time using a beaker and a stopwatch
Change the flow rate by operating the needle valve and repeat steps 5 and 6 to have 6-7 records

High Flow Rates

Connect the output of the hydraulic bench to the inlet of the test pipe directly
Turn on the hydraulic bench pipe and adjust half open the supply valve
Fully open the needle valve of the test pipe at the downstream to pass the water through it
Bleed the trapped air as necessary using the bleed pipe and connect the hand-held pressure meter
Record the pressure meter readings.
Measure the discharge by collecting a known amount of water in a given time using a beaker and a stopwatch
Change the flow rate by operating the needle valve and repeat steps 5 and 6 to have 6-7 records

Identify laminar and turbulent flow from lower flow results and identify the transition point (look at the Hydraulic gradient VS Flow velocity plot)
Get the slope of the i VS u plot (i/u) from the laminar flow results. Use the following equation to calculate the water viscosity: $$\mu = \frac{i}{v}\frac{\rho gd^2}{32}$$

Check this theoretical value with the value used in this experiment. In the equation above, make sure you are putting $\frac{slugs}{ft^3}$ for $\rho$

How do lower and higher flow results compare?
For the higher flow $log/log$ plot, get the slope, $n$ from the most linear part, and check it with the relation ${i}\propto{v^n}$
What are some of the sources of errors?
Discuss the practical applications of this experiment

Low Flow Rates

High Flow Rates