Pusher or Ducted Fan

[mig29n]

Hi,

Which one is the best to choose?

[flyfalcons]

Depends on the application, but pushers usually have better thrust than ducted fans, allowing you to fly with a small/lighter powerplant. You can get more speed from a fan but you need a large power supply, which can be prohibitively heavy in smaller models.

[Tony Oliver]

Er, do you mean 'which is the best - ducted fan with the engine infront of or behind the fan'?

I don't know for sure, but I would think the engine infront would provide a cleaner exhaust to allow the airflow to accelerate better. The upwind end would not be so badly affected by the turbulence around the motor.

Just my thoughts - no empirical evidence.

Tony

[flyfalcons]

Ah, because of the change in original question I'll retract my first post. My T-33 has the motor behind the fan. My feeling is the fan is happier and more efficient when the inlet air is less turbulent, but I'm no DF expert.

[mig29n]

Hmm ... if that is the case why I see a lot of people selling tractor fan and not much people selling pusher type of ducted fan ...:)

[flyfalcons]

Who are you replying to?

[mig29n]

To the group

[flyfalcons]

Originally posted by mig29n
Hmm ... if that is the case why I see a lot of people selling tractor fan and not much people selling pusher type of ducted fan ...:)

Probably because the tractor style is a better arrangement.

[mig29n]

ByroJet Fan is a push or tractor ?

[gregg f]

Originally posted by mig29n
ByroJet Fan is a push or tractor ?

pusher
here's a pic of installation http://www.usrcjc.org/kits/Byron/man16pic.PDF

[monkamarm2000]

Byron Fans if you can get a hold of one have tons of thrust and work well. I say run a tractor fan for one reason only, the exhaust runs straight back. On my Byron units it has to go foreward into the fuse( usually the tighter thinner nose parts) and builds heat and mess. And if you want thrust just run a 6" hurricane fan unit. When and if my 6" units fail I will replace them with that


Barry

[JetMang]

Mig29n,

The tractor style fan is the industry standard when it comes to ducted fans. It is actually a better arrangment. You can route the exhaust straight back, there is sufficient engine cooling, and can be made quite aerodynamically efficient. It is easier to build an integrated high performance propulsion system in a tractor configuration than a pusher.

The Byron fan (pusher) will get you thrust, but won't get you a very high top end speed. Though it works well, it doesn't perform like the tractor setups that are commercially available.

Chris