Linked Questions

2 votes
1 answer
2k views

Is there a mathematical formula to find the most efficient propeller? [duplicate]

Is there a mathematical formula to find the most efficient propeller? Is a five-blade better than a four-blade? Does software exist to aid in the calculations there?
AirbusLover's user avatar
32 votes
2 answers
44k views

What are the advantages of more than 4 propeller blades?

I have heard that propellers with more than four blades are not as efficient as 4 or less blades because of lower thrust which may result from interfering prop-streams. But I see the ATR-42/72 and ...
SMS von der Tann's user avatar
23 votes
4 answers
4k views

Would an aircraft with contra-rotating propellers longer than the plane's wingspan be able to fly?

I enjoy taking the time to try and visualize how fictional aircraft might actually work in reality. Unfortunately there are some that seem highly impractical from an engineering student's point of ...
Kyle Lowery's user avatar
26 votes
2 answers
10k views

Is it possible to fly with counterbalanced single blade engines?

Refer the image for counterbalanced single blade (Source http://www.aviastar.org/helicopters_eng/bo-103.php). In ground school, they took us for aircraft inspection at end of our ground school ...
Lucky's user avatar
  • 1,932
18 votes
4 answers
9k views

Why is max endurance different for jet and props?

Max endurance speed is not the same for gliders, propeller planes (also for turbo prop, right?) and jet planes. While for for jet planes max endurance is at the minimum drag speed ($V_{md}$), for ...
yankee's user avatar
  • 1,073
16 votes
5 answers
4k views

Why is thrust inverse to speed in piston engines?

It is said that piston engines have constant power output, and thus their thrust is inverse to speed (e.g. here), while turbines have relatively constant thrust. I'm looking for an intuitive ...
ciamej's user avatar
  • 293
28 votes
1 answer
18k views

Is there any equation to bind velocity, thrust and power?

I am designing a remote controlled airship. I will tune it so that the lift given by Archimedes' Principle will exactly balance the weight of all the structure. It will be propelled by brushless ...
Matteo Monti's user avatar
10 votes
4 answers
3k views

How can best glide speed be lower than best rate of climb speed?

I was looking up V-speeds for C172. I don't have easy access to an official copy of the POH, but online I found: $V_y$, best rate of climb speed (at sea level): 76 KIAS (p22) $V_{glide}$, maximum ...
Jan Hudec's user avatar
  • 56.3k
11 votes
7 answers
3k views

Explained intuitively, why does aspect ratio affect induced drag?

Over the last few hours, I've been trying to intuitively understand induced drag, and how aspect ratio affects it. I already know the equations, but while they explain the relationship, they do not ...
RapidPotato's user avatar
6 votes
5 answers
3k views

What determines maximum speed of a propeller aircraft - Thrust or Power?

I'm reviewing training materials1 for straight and level flight. The content focuses on drag types and explains that the required thrust curve is equivalent to the total drag curve. It then introduces ...
Crabsticks's user avatar
4 votes
4 answers
2k views

Is there any theoretical problem powering the fan with an electric motor [duplicate]

A question that I have been wondering about lately is whether it would be possible to power the fan in a modern hi-bypass turbofan with an electric motor and achieve performance comparable to the ...
erikkallen's user avatar
6 votes
5 answers
9k views

Guidelines for using a constant speed/adjustable pitch propeller

I have been trained in a single engine fixed pitch prop ( C152). I'm trying to move to Piper Arrow II which has an adjustable pitch propeller. I understand how constant speed propellers work. I'm ...
Prashant Saraswat's user avatar
12 votes
2 answers
6k views

How is the induced drag calculated for a wing with elliptical planform?

How is the induced drag calculated for a wing with elliptical planform ? Is this wing shape the most efficient ?
Earl Quandt's user avatar
7 votes
3 answers
5k views

What is compressibility drag?

I don't mean wave drag here. What is compressibility drag, which is understood to be a form of miscellaneous drag?
Guha.Gubin's user avatar
5 votes
4 answers
2k views

Can this design provide more lift force than thrust from engine?

The problem is depicted in the picture: Generally, why we don't use engine blow wings to fly? Can we use wind-tunnel-like wing to generate lift force? Can it generate more lift than thrust? If it ...
Libo Liu's user avatar

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