# Thrust producing pressure

1. Aug 1, 2007

### Subaru_STI

If I have a RC electric ducted fan engine blowing at 8 lb of thrust into a closed container, what PSI would it be inside of the container, (when the engine is runny continuously)?

Thanks

2. Aug 1, 2007

### Staff: Mentor

Depends on the size of the container and how the stream is captured. For a coherent stream of air hitting a wall, you can take the force and divide by the area.

3. Aug 1, 2007

### Subaru_STI

I am basically making a battery powered supercharger for a car. the motor will be fitted into the intake tube.. can you get a rough idea from that?

4. Aug 1, 2007

### rcgldr

Your statement implies that there's a net pressure differential between the contaniner and the outside air that results in 8 lbs of force at the fan. Also, there's no blowing, the ducted fan is acting as a compressor if it's output is going into a closed container. The pressure would be 8 lbs divided by the cross sectional area of the duct containing the fan. If the duct has a diameter of 4 inches, then the area of the duct is pi x r^2 = pi x (2)^2 = 12.566 in^2. Pressure would be 8 lbs / 12.566 in^2 ~= .636 psi.

Last edited: Aug 1, 2007