- #1

- 3

- 0

## Main Question or Discussion Point

Hi everyone,

I have a general question on fluid speed for air.

What would be a reasonable design limit velocity for air?

Assuming that it does not pass the speed of sound which can bring an whole set of other problems 1116 ft/s = 761 mph at sea level.

Would 900ft/s be a reasonable limit?

Here is a little background on the problem. I am designing an electric motor cooling system with different size ducting/channels. As we all know through fluid dynamics, the velocity is a function of area/mass flow. I can change the area/mass flow to increase/decrease velocity. The velocity will determine my heat coefficient, which I am trying to optimize for each section of the cooling system. I have velocities from 2 to 900 ft/s in the system. I am trying to find the upper design limit for velocity but there are very little information on the web.

Thank you for reading this.

Alvin

I have a general question on fluid speed for air.

What would be a reasonable design limit velocity for air?

Assuming that it does not pass the speed of sound which can bring an whole set of other problems 1116 ft/s = 761 mph at sea level.

Would 900ft/s be a reasonable limit?

Here is a little background on the problem. I am designing an electric motor cooling system with different size ducting/channels. As we all know through fluid dynamics, the velocity is a function of area/mass flow. I can change the area/mass flow to increase/decrease velocity. The velocity will determine my heat coefficient, which I am trying to optimize for each section of the cooling system. I have velocities from 2 to 900 ft/s in the system. I am trying to find the upper design limit for velocity but there are very little information on the web.

Thank you for reading this.

Alvin