[MUSIC PLAYING] Good morning everyone.
Welcome to your fluid mechanics experiment number two.
In this experiment, you will measure the pressure distribution around a cylinder in the crossflow.
In order to do this experiment, you need a wind tunnel, the water manometer, and of course,
the specially designed cylinder.
We will mount the cylinder in this way, and then the airflow will be in this direction.
This specially designed cylinder has 10 holes on the surface.
Each hole will be connected individually to a tube like this.
And each tube will be later individually connected to the water manometer.
So when we mount the cylinder into the working area of the wind tunnel, hole number one will
be horizontal.
So we'll I actually measure the pressure distribution at the zero degree angle.
Hole number two, we'll be able to measure the pressure distribution at a 20 degree angle.
Hole number three, we'll be able to measure the pressure distribution at 60 degree angle.
So that's how we measure the pressure distribution over the surface.
Now we need to mount the cylinder to the wind tunnel.
Remember to align the pin with the support on the other side of the wind tunnel.
Also remember you need to align those two markers to make sure that hole number one
will the zero degrees, which is the horizontal direction.
Lock the two wires.
Then we need to connect the cylinder to the water manometer with the quick release 10-way
connector.
It has to make a good contact, and lock the device.
Now the cylinder is ready to use.
We now can power on the wind tunnel, then come to the computer, click on the icon on
the desktop, and pick up [INAUDIBLE], and click on Load.
You will see a pop up window like this.
First thing we need to do is change the temperature value from 18 degree to 25 degree.
This is the temperature in this lab.
And you also noticed that watch dog enabled has been illuminated, which means now the
connection between the wind tunnel and the software on the computer has been built.
So we will be able to start to use the wind tunnel right now.
So we can start the fan.
You click the fan on, the number will be automatically changed from 0 to 1.
Now we can increase the fan speed from zero potential to 20% percent of potential.
You will see the fan's not running.
Wait for about 60 seconds to let the air flow become stable.
Then you can start collecting your first set of data.
Your first set of data will include the velocity of the air flow, which provided from the software
right now, is about 6.5 meters per second.
Then you need to come to the water manometer to record the data in the water tubes.
Be careful that when you read the water level in the water manometer, you have to bend down
like this.
Make sure your sight is perpendicular to the water panel, so you get high accuracy rate.
So this will be your first set of data.
Then you can increase the fan speed to 30%.
Again, you have to wait for another 60 seconds to let the air flow become stable.
Then you can start collecting your second set of data, which includes the air velocity
right now is about 8.8 meters per second.
And also you need to come over here to the water manometer to read the water levels in
the tubes.
After this, you can increase the fan speed to 40%.
Every time, remember you have to wait for 60 seconds to let the air flow become stable.
Then you can collect the data.
So 40% will be your third set of data.
Which includes the air velocity right now is about 11.1 meters per second.
And again, you need to come to the water manometer to read the water level in the water manometer
carefully.
Repeat the same steps until you reach 100%.
Remember for 100%, you also need to wait for 60 seconds, then collect your last set of
data.
Then gradually slow down the wind tunnel, and this will be your second experiment in
fluid mechanics.