Ducted Fans on 20' Blimps?

[tschwartz1]

On a 20' Blimp are ducted fans good power sources?

If not, what sort of electric engine/prop configurations work best?

Ducted seems clean and high on the coolness factor but I understand they are not as good at lower speeds.

Any thoughts?

Tony

[Majortomski]

Ducted fans= cool, efficient at blimp speed NO.

Big slow turning props are your best bet.

How big and how pitched is a function of how fast you think your blimp needs to fly. Personally I wouln't consider an out door blimp unless it could easily do and maintain 40 MPH. That gives you some ability to out run a wind front.

Have you given any thought as to how you're going to trailer and transport your blimp? You're looking at at least two "T" sized bottles of helium per fillup, that's at least $180.00.

[drisok]

I would not recommend ducted fans on a blimp.

We have experimented with many different prop configurations and finally settled on a custom prop. While our props are anything but turning slow, we have foud that a 4 blade configuration works incredibly well.

Our blimps will move forward at 30 mph so 40 mph might be a stretch with current engine/weight configurations. remember larger engines=more fuel=less time in air=more time on ground=less fun.

If you are dumb enough to be in the air when winds are sustained 30+ mph or you can't see that storm coming in then you shouldn't have been in the air in the first place. Common sense prevails when flying a blimp. Nothing happens quickly. Turns are slow and calculated and throttle is tempered not jerky or uncontrolled.