What is the horsepower motor needed to drive 2 blades x 1 meter diameter aircraft pro

[Guest jhmichael25]

If I am in the wrong place, please redirect me to right one as this is my second post ever on this discussion forum.

 

My query may be too simple for you to answer, but to me is obviouly not.

 

Let's say I have an aircraft propeller of 2 blades having in total 1 meter diameter, what horsepower motor will I need to drive it to speed up to 100knots?

 

 

[Guest High Plains Drifter]

What is the horsepower motor needed to drive 2 blades x 1 meter diameter aircraft pro

If I am in the wrong place, please redirect me to right one as this is my second post ever on this discussion forum.

 

My query may be too simple for you to answer, but to me is obviouly not.

 

Let's say I have an aircraft propeller of 2 blades having in total 1 meter diameter, what horsepower motor will I need to drive it to speed up to 100knots?

jhmichael25,

 

The people who understand these things will probably need more info.(I dont know much about it)

 

At a basic level a propellor blade is just a wing, as you are probably aware there are many different wing types for different jobs.

 

As you do not mention what airframe you will be propelling, I will assume a wind tunnel experiment.

 

Perhaps you could expand your question a bit ?

 

HPD

 

 

[Guest jhmichael25]

jhmichael25, tunnel experiment.

Perhaps you could expand your question a bit ?

 

HPD

Thank you High Plains,

 

At that stage is just for an experimental purpose and not to any specific airplane. It's more to enrich my poor knowledge of aircraft and also as part of a

 

school assignment for next year.

 

 

[Guest High Plains Drifter]

At that stage is just for an experimental purpose and not to any specific airplane. It's more to enrich my poor knowledge of aircraft and also as part of a school assignment for next year.

jhmichael25,

 

You will need to explain the project a bit more.

 

HPD

 

 

[Guest disperse]

There are calculations for this sort of thing.. but that seems to be a rather small prop. A jabiru LSA 55 at around 450kg has a 80-85hp engine and will cruise at around 100kts at about 70 to 75% power. But for the big calculations fist you need to calculate drag and weight and also the efficacy of the prop. Then you can calculate the required hp

 

there are web sites with more on this ...... just can't put my finger on them

 

 

[Guest disperse]

Hers the site I was thinking of http://www.zenithair.com/kit-data/ht.html

 

see what you find there.. and someone may add some more here

 

 

[Ultralights]

i have quite a few Aeronautical engineering text books in PDF format you might want to have a look at, though these go quite in depth with page after page of equations, covering things such as tip vortex rotation, airscrew co-efficients, thrust co-efficient etc etc etc

 

the book is aerodynamics for engineering students.

 

 

[youngmic]

G,day jhmichael,

 

To drive it to 100kts?

 

I'll asume you mean the aircraft itself and not the propeller blades, if you just wanted to turn a zero pitch propeller of 1m dia. to a tip speed of 100 kts then around <5hp would do it. With increasing pitch so the horsepower required will also increase.

 

If you wish to overcome the total drag of an aircraft to enable it to do 100 kts on a 1m propeller then the answer probably starts at around 50 hp for a very small, sleek little aircraft that will carry a person and 10 or 15 hp for a model aircraft to do 100kts. The hp required will keeping going up with the size of the aircraft and its increasing total drag.

 

But for a few random examples a 28 hp engine will turn a small (1m) prop at around 6000 RPM and develop enough thrust to enable a very light single place ultralight to fly at around 60kts, a ceiling fan is sub one horsepower at full noise and a truck radiator fan absorbs about 10 horsepower, and the Wright Flyer (young Orville and Wilbur) had about 12 hp to turn two very large diameter propellers at around 250 RPM.

 

Thrust for thrust, a larger dia. slower turning propeller is always much more efficient than a small dia. high RPM propeller.

 

Hope that's a starter, if you need better than that post some specific details, and I'll find the answer.

 

Just had a side thought, you're not trying to build a wind tunnel are you? If so we're heading in the wrong direction with a 2 bladed prop., but it could work, sought of.

 

Regards

 

Mick

 

 

[Guest jhmichael25]

Hi Disperse

 

Hers the site I was thinking of http://www.zenithair.com/kit-data/ht.html see what you find there.. and someone may add some more here

I have followed through and found it very interesting. There are so much in there and to absorb 1/10 of we need a good couple of hours spending. Worthy a while for every minute spent on the site.

 

Thank you so much for sharing.

 

jhmichael25

 

 

[Guest jhmichael25]

G,day jhmichael,To drive it to 100kts?

 

I'll asume you mean the aircraft itself and not the propeller blades, if you just wanted to turn a zero pitch propeller of 1m dia. to a tip speed of 100 kts then around <5hp would do it. With increasing pitch so the horsepower required will also increase.

 

If you wish to overcome the total drag of an aircraft to enable it to do 100 kts on a 1m propeller then the answer probably starts at around 50 hp for a very small, sleek little aircraft that will carry a person and 10 or 15 hp for a model aircraft to do 100kts. The hp required will keeping going up with the size of the aircraft and its increasing total drag.

 

But for a few random examples a 28 hp engine will turn a small (1m) prop at around 6000 RPM and develop enough thrust to enable a very light single place ultralight to fly at around 60kts, a ceiling fan is sub one horsepower at full noise and a truck radiator fan absorbs about 10 horsepower, and the Wright Flyer (young Orville and Wilbur) had about 12 hp to turn two very large diameter propellers at around 250 RPM.

 

Thrust for thrust, a larger dia. slower turning propeller is always much more efficient than a small dia. high RPM propeller.

 

Hope that's a starter, if you need better than that post some specific details, and I'll find the answer.

 

Just had a side thought, you're not trying to build a wind tunnel are you? If so we're heading in the wrong direction with a 2 bladed prop., but it could work, sought of.

 

Regards

 

Mick

G'day youngmic,

 

By the way thanks heaps for your input and my question is now pratically answered.

 

No, I am not trying to build a wind tunnel. But I have in mind in doing a lot of experimentation. I am just a very basic beginner with great appetite to learn more and more, plus working toward in getting my commercial licence one day.

 

I have made blue and bolded the tips you gave me as they have helped me to understand a little better the concept across propeller and hp relationship.

 

Thanks very much for all the tips received from you and received also from other members. I have honestly appreciated. We may bump again in the near future at any time in this forum.

 

May I take this goldie opportunity to not only thank everydody but also to wish a Merry Christimas and a safe long holiday on this special occasion.

 

Cheers,

 

jhmichael25