Questions tagged [propeller]
Aircraft propellers are airfoils which convert rotary motion from a piston or turbine engine into thrust suitable for propelling an aircraft.
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Is possible to stick two '2-blade' propellers to get multi-blade propeller?
Does propeller blades' airflow interfere with each other blades and decrease overall thrust? Should I consider high pitch propeller for this purpose?
My purpose: I'm looking for a 20-inch four-blade ...
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If an elliptically-shaped aerofoil gives the optimum lift distribution, why aren't propeller blades designed around this ideal?
So given an elliptical lift distribution is the most efficient, why are propellers not designed around this? Props aren't affected by the adverse stall characteristics that concern a "main", ...
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For a same propeller solidity, what are the tradeoffs between blade activity factor and blade number?
In order to absorb more power for a given prop diameter, we can design the propeller with a higher activity factor-- basically what amounts to wider blades-- or we can also design it with more blades. ...
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What is the result of increasing number of propeller blades on the same engine [duplicate]
For example Rotax 912. We can meet this engine with 2 and 3 propellers mounted. Or compare airplanes equipped with engines with pretty the same power output i.e. C152 with Lycoming O-235 - 110 HP and ...
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Deicing Rod for Propellers
Similar to a card hitting the spokes of a bicycle, the card is soft enough to knock the dust off the spokes with no damage. What material would be best to impede the propellers to chip off the ice. ...
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Why does a force on a propeller act 90° "ahead" due to gyroscopic precession?
This is a common explanation:
A tailwheel airplane is on the takeoff roll and the tail comes up, the
propeller disc rotates forward. That's akin to someone pushing on the
top of the disc. The force ...
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Does a constant speed prop maintain the optimal angle of attack at all time?
From an answer on this site:
The governor just knows: Speed too fast, flyweights move out, routes
pressure to move the blades more coarse; speed too slow, flyweights
move in, routes pressure to move ...
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How would flow angle change along the length of a propeller airfoil?
Let's assume I have:
windspeed of 15 m/s
blade length of 10 m
rotational speed of one revolution per second
Can someone please help me calculating how the flow angle would change along the length of ...
user54043
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How does one choose the number of blades and the diameter required for a turboprop propeller?
I am interested in the preliminary design of a regional aircraft that uses turboprops as the propulsion method.
Following considerable research online about propeller design (disk theory, BEM...) I am ...
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What is the physical difference between an airplane having let's say 150 horsepower to an airplane having 250 horsepower?
I was wondering what defines horsepower in an airplane piston engine and how can it be changed?, is horsepower changing during flight?
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How to do blade element momentum theory analysis for different geometries of airfoil, e.g. NACA airfoils?
I want to analyse NACA airfoils using BEMT. I have only yet done it for basic symmetric airfoils. I would like to know what all assumptions remain same in NACA airfoil analysis and to what degree it ...
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Is high propeller pitch inherently inefficient?
For an airfoil, in general, the aerodynamic force is more or less perpendicular to the chord line.
A low-pitched propeller blade has it's chord line more perpendicular to the direction of flight, ...
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Would large, low aspect ratio fan/propeller blades be more efficient? Why not?
With reference to this answer
We read in the above that accelerating a larger mass of air by a smaller amount is (theoretically) more efficient. This is an advantage of a larger propeller than is ...
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Help in understanding this velocity triangle of a propeller
I was reading a research paper and have had difficulty understanding something. How did the author get tan(phi) in these terms?
This is something I've been trying to figure out for a long time now.
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Relationship of propeller RPM, blade pitch, and drag at very low blade pitch angles
I'm researching the 2016 crash of a PIA ATR-42 in Pakistan, the report on which was recently released. Link to the report: https://www.caapakistan.com.pk/Upload/SIBReports/AAIB-386.pdf
During the ...
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How much do propellers stutter?
A photo in EAA's monthly magazine shows one propeller blade as a dozen distinct images rather than the usual smooth motion blur. One explanation (this answer appears to have been deleted) for this is ...
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Will the blade angle of a constant speed propeller be at its least angle (fine pitch) during full throttle and prop full?
During low power settings, low throttle setting and prop full during taxi, the blade angle will be at its finest pitch. As we increase the throttle for take-off, will the blade angle remain in its ...
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What is a typical compression ratio in light turboprop aircraft propellers? [closed]
Does anyone happen to know a rough estimate of a typical light turboprop aircraft propeller's compression ratio? Something with 6-12 seats like a Cessna Caravan or Piper Malibu. Doesn't need to be ...
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How can I find the maximum climb angle of a propeller driven aircraft from a graph of vertical velocity against airspeed?
I've been asked to find the maximum climb angle of a propeller driven aircraft from the graph of vertical velocity against airspeed:
How can I do that?
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Why aren't thermal analysis of propeller done?
I have searched for articles on Thermal Analysis of Propeller but couldn't find one. Can I assume the aircraft company don't perform heat transfer simulation and analysis of high speed propeller? Isn'...
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What other advantage(s) does an adjustable prop give you?
From what I understand, the purpose of a variable-pitch propeller (be it manually adjustable, or constant speed) is that it allows the engine to always operate at its most efficient speed, much like ...
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Do jet aircraft have a better glide ratio than propeller aircraft in general? If so, why?
Being fond of aviation, I play with software simulators a lot.
I have noticed that while jets seem to be able to glide for a long distance even at zero throttle, propeller aircraft need to be ...
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How can a small ducted fan produce a large amount of thrust?
This 15.2 cm ducted fan by Schuebeler can produce 175 Newtons of static thrust. How is this possible in such a small diameter?
If this seems normal, then why and how can this ducted fan produce that ...
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What factors determine magnitude and orientation of induced velocity at propeller blade?
• Magnitude
What factors determine magnitude of "Vind" (induced velocity)?
• Orientation
If we take analogy with induced velocity at wing,isnt "Vind" must be prependicular to Vr?
• ...
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Is "V/n" geometric or effective pitch in advance ratio formula?
V is the freestream fluid velocity, typically the true airspeed of the aircraft or the water speed of the vessel
n is the rotational speed of the propeller in revolutions per unit of time
D is ...
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Is flow attached at fixed propeller blade at every RPM / speed conditions?
Propeller blade AoA depends on tangential veloctiy caused by rotation and forward speed "head wind".
If propeller has fixed pitch is flow attached on blade at every RPM / speed conditions?
...
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What is engine power vs propeller thrust relation?
Given:
speed 30 knots
engine power 70 hp at 5800 RPM
propeller 3 blades, diameter 14 inch, pitch 17 inch, at 2300 RPM
fluid density 1023 kg/m3
I know that each blade is basically one wing. ...
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Does ducted fan require more engine torque than unducted-fan,at same RPM?
Two identical fans, one is unducted and other is ducted,both operate at same RPM.
•Does ducted fan require more engine torque than unducted-fan ,measured both at same fan RPM?
power=torque x RPM so ...
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Could propeller wash provide sufficient lift to take off - even in theory?
I know this seems a crazy thing to ask but it is not the same as lifting oneself by the bootstraps. If you try to lift yourself that way, there are two equal and opposite forces, yet there are ...
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Does propeller size affect total drag force of plane?
Integration of pressure distribution of each blade get net force(thrust) which is allways pointing forward.So there is no drag force at any propeller ,that tells that size of propeller doesnt ...
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Clarification on autogyro thrust formula
I'm slightly confused regarding the formula quoted here:
How to calculate the amount of thrust of a autogyro during auto rotation?
When they say thrust is equal to the weight. Do they mean use earth ...
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Are the A400M propellers rotating in the wrong way in "Mission Impossible: Rogue Nation"?
At the beginning of the movie Mission Impossible: Rogue Nation we can see an A400M taking off.
When the engines start, the propellers turn in opposite directions. As I understand it this is not a ...
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Does a constant power prop exist? What are the tradeoffs compared to a constant speed prop?
Variable-pitch props allow pilots to adjust the angle of attack of the propeller to change the load on the engine.
The most common implementation of this is a constant speed prop where the prop ...
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How does 'standalone' propeller efficiency change with altitude?
I've seen questions regarding propeller aircraft and altitude and their interaction. But I'm wondering what the relationship between just the propeller and altitude (changing air density) is. How does ...
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Is propeller wake turbulence quantifiable based on operating conditions?
I know the propeller does work on the air and thus the flow behind a propeller is higher than the airspeed. However, what is the quality of this flow? If I were doing a heat transfer analysis of an ...
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How can jet engines be more efficient than propellers? [duplicate]
If jet engines are smaller in diameter than propellers, is it fair to say that propellers accelerate a lot of air a little while a jet engine accelerates a little air a lot? Basically, a jet engine ...
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In an engine failure, should I expect less range than with the engine in idle?
I fly a C172 (fix pitch propeller) and when my instructor and I practice a simulated engine failure, we do not turn off the engine, instead we set the engine to idle.
In an actual engine failure, ...
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Do the blades of the rear disk have different geometry to the blades of the front disk on a contra-rotating assembly?
If my understanding is correct, the air flow is accelerated by the front propeller toward the rear propeller in a contra-rotating prop assembly. Therefore, the rear disk would be receiving air at ...
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Why does disk loading mean anything when rotors/propellers are not disks?
"The helicopter rotor is modeled as an infinitely thin disc with an infinite number of blades that induce a constant pressure jump over the disk area and along the axis of rotation."
This is ...
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How does the location of a propeller affect an aircraft's stability?
Some aircraft possess propellers on front of the fuselage, like the Cessna 172, and some aircraft have propellers located at the rear of the fuselage, like the Velocity 173RG-E.
How does the ...
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How do propeller planes sync their propellers?
While reading this question, I found that the answers did not address the point I had come for. On planes with electronic propeller synchronization, how is it actually accomplished? I know why ...
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Are there any aircraft powered by tip jets in the propeller blade?
I am familiar with tip jet powered helicopter experiments. Is there any aircraft that use/used this mode and would it be useful to use a tip jet driven prop on aircraft instead of piston or turbine ...
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What is the definition of "geometric pitch angle" for a propeller?
My question is regarding the geometric pitch angle of a propeller. Is it the angle between the rotational/propeller plane and the zero lift line of the particular airfoil at a propeller section? Or is ...
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What are the design considerations for variable-pitch folding-propellers?
Folding props are increasingly used on self-launch gliders in order to reduce drag. Here is an example of 1m dia. props from LZ Design's FES system:
For self-launch gliders, due to minimally-sized ...
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What are the advantages/disadvantages of a forward-folding propeller?
The AMS Carat A is a motorglider with a forward folding propeller.
To my knowledge, this is the only production plane with this characteristic. The most popular self-launching gliders with front ...
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Why do the ratio of proppeler plane over jet engine seems to have change in Bucarest airport during the covid19 crisis?
I live in a village very close to an (intl) airport: Bucharest "Henri Coanda" International Airport.
Now, due to lock-down caused by covid pandemic, I noticed - at least today when I spent most of the ...
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How can I calculate the relationship between propeller pitch and thrust?
I am trying to design a WWI propeller so I started calculating. The propeller comes with a specified pitch of 1.75m. The engine is supposed to run at around 1900 rpm and 147kW. These are most likely ...
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Why are highly cambered airfoils rarely used in propellers or wings?
Highly cambered airfoils like the Seligs and Epplers are hardly ever used in propeller or wing sections. Why?
Does their performance reduce at high Re? Are they only adequate at low Mach, low Re?
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How big is the TP400-D6 turboprop installed on the A400M?
I am trying to re-create the A400M TP400-D6 engine in CAD, mainly the nacelle and propeller, yet I can't find any detailed dimensions for it.
Europrop specifies a 0.92m diameter for the TP400-D6, so ...
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Was Ludwig Wittgenstein's aircraft propeller ever built?
Ludwig Wittgenstein designed (and received a patent for, at the remarkable age of 22) an aeronautical propeller.
Wikipedia describes it:
Wittgenstein’s design required air and gas to be forced ...
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