Gas Dynamics

What is it?

Pneumatics is all about the mechanical properties of gases like air.

Did you know?

Gas dynamics and pneumatic systems are the backbone to most mechanical systems.


Gas Dynamics at ResMed

At ResMed we use the principles of gas dynamics and pneumatics to design a system that generates lots of pressure but at the same time is very quiet so it doesn’t disrupt people’s sleep.

We rotate an impeller (kind of like a fan) very very quickly to try and generate pressure.

Gas Dynamics used to improve noise

If you imagine being on spinning equipment on a playground, as it spins faster, you get more and more stuck to the outside of the equipment. It’s the same thing if you are in a car that turns a corner quickly – you get pushed to one side. That’s due to centrifugal force and that’s what happens in our blowers as the air gets spun by the impeller, it moves towards the outside and in the process it generates pressure.

Now, if you are on the spinning play equipment again and want to get off, if you jump at just the right moment, you can land safely, but if you go too early or too late, you will fall. The same concept applies in our blowers, if the air leaves the impeller at the wrong angle, it will be very noisy and turbulent, but if we get the angle just right, it will be quieter.

Did you know?

The unit of measurement for pressure is a pascal which was named after French physicist and mathematician Blaise Pascal

Test your knowledge of Gas Dynamics

What elements make up air?

What type of fluids does a pneumatic system use?

What unit is used to measure pressure?

Explanation: A 'Pa' is is one N/mm^2

What is the difference between gauge pressure and absolute or total pressure?

What is the type of fluid flow when the fluid gets out of control?