# Increase Air Speed at outlet

I have a set up that inflates a rubber jacket in order release the metallic rings from underneath it. I am currently having issues with not having enough pressure (force) at the outlet to inflate the rubber jacket. I want to reduce the size of the pipe in order to increase the velocity, will this work?

• Reducing the diameter of the pipe will increase velocity at the outlet, that's for sure. – Gert Dec 15 '18 at 17:00
• A diagram of the setup might help? – Chet Miller Dec 15 '18 at 17:40

## 1 Answer

Assuming somewhat approximately the gas is in-compressible, then (continuum equation):

$$v_1A_1\approx v_2A_2$$

where the $$A$$ are the cross-sections of the pipe.

So we can write:

$$v_2\approx\frac{A_1}{A_2} v_1$$

Using diameters $$D$$:

$$v_2\approx\Big(\frac{D_1}{D_2}\Big)^2 v_1$$

So fitting an adaptor with $$D_2 will increase $$v_2$$.