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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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5 votes
3 answers
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How can I find the minimum and maximum airspeeds for efficiency with a specific prop/engine combination?

I'm operating a Cessna 180 with various wing and weight mods with a TCM IO550D engine and a McCauley Black Mac (D3A34C401/90DFA-2 3 blade (88 inch) seaplane prop. I operate Lean of Peak (LOP) for most ...
DustyFlier's user avatar
1 vote
0 answers
73 views

Could a WW2-era Grumman Hellcat land on a Saipan-class light carrier using only reverse-thrust generated by a reverse-pitch propeller?

Just that - take away an F6F's arrestor hook and fit it with a reverse-pitch-capable propeller (and, of course, all the other odds-and-ends to make such a system work). Would it be possible for a ...
Flippy DaFlip's user avatar
2 votes
1 answer
130 views

How to design a propeller that works efficiently in reverse?

I'm designing a UAV that needs to reverse motors for some maneuvers, but unfortunately most of the commercially available propellers I've tested are optimized for single direction and only produce ...
CaptainCodeman's user avatar
2 votes
2 answers
159 views

Determining Sectional Drag Coefficient Using Propeller Geometry

Im trying to teach myself blade element theory for helicopters and propellers, but im getting quite confused. Most of the papers and textbooks I read will reach an equation for differential thrust ...
TryingMyBest's user avatar
3 votes
1 answer
169 views

Where does "wasted" propeller power go?

Aircraft propellers are very efficient, with around 80-90% of input horsepower being applied to axial flow. However, that raises the question of where the remaining 10-20% of energy goes. I'm ...
Riley Rosell's user avatar
3 votes
1 answer
167 views

Is the math behind my approach to design a propeller right?

I'm trying to design a fixed pitch propeller of diameter 1.8 m flying at 10000 ft going at forward velocity(85 m/s). What I've done is take a series of airfoils (from root to tip), found the ...
vaishnavi gowrishankar's user avatar
0 votes
0 answers
54 views

How can I cross verify my propeller thrust? [duplicate]

I'm simulating a propeller in Ansys and im getting a thrust of 2000N. The forward speed is 85m/s and 240.25 rad/s angular velocity and the diameter of the propeller is 1.8m. Since I'm not able to find ...
vaishnavi gowrishankar's user avatar
0 votes
0 answers
28 views

how can we calculate normal force or vertical component of propeller in an aircraft?

when we calculate thrust of an propeller engine we also face to vertical component or normal force which change neutral point of an aircraft how can we calculate this force? thank you
almohndis's user avatar
3 votes
2 answers
229 views

What's the thrust of a given propeller at zero airspeed?

If memory serves correctly, propeller thrust for a given propulsive horsepower is inversely proportional to airspeed, assuming features like constant RPM prop, and being outside Mach Effects The ...
Riley Rosell's user avatar
1 vote
0 answers
58 views

How to retrieve the thrust distribution over a blade using XROTOR?

What is the procedure for retrieving the thrust distribution over a propeller blade using XROTOR? I need the sectional (i.e., for each station) thrust coefficient values. I was only able to retrieve ...
floyd123's user avatar
2 votes
1 answer
102 views

When discussing a “feathering, counterweighted propeller” where are the counterweights?

We are learning about propellers in school. To my understanding, generally a non-feathering, non counterweighted prop uses centrifugal twisting moments to lower blade pitch while oil pressure is used ...
hmshood56's user avatar
3 votes
1 answer
99 views

What does "Rotating airfoils of engines" mean in the US Code of Federal Aviation Regulations?

In part 1.1 of the US 14 CFR, definitions and abbreviations, a propeller is defined as: ...a device for propelling an aircraft that has blades on an engine-driven shaft and that, when rotated, ...
nkrom's user avatar
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2 votes
1 answer
166 views

Is there a standard way to identify propeller blades?

Obviously, as Julio pointed out, Chuck's method of identifying propeller blades is ineffective. Is there a standard way to identify blades, other than tautological statements like "There is a ...
Someone's user avatar
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0 votes
2 answers
206 views

Does propeller width have a material impact on thrust? [closed]

I have seen propeller thrust calculations and they do not appear to have the variable of propeller width. They only use diameter or radius. What if any impact does width of the propeller have? Here is ...
Aaron's user avatar
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1 answer
140 views

Hypothesis: swept back propeller would reduce drag and increase thrust [duplicate]

Hypothesis: swept back propeller would reduce drag and increase thrust. Any experience with this?
Aaron's user avatar
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0 answers
95 views

Deriving Accurate Exit air velocity of rotor

My goal is to derive the equation for exit air velocity as a function of: Pitch angle RPM Rotor Radius Constants like ρ Assumptions: Vc is relative velocity of air upstream, and is = 0 Inflow is ...
Luke-McDevitt's user avatar
2 votes
5 answers
514 views

Can an airplane propeller become supersonic?

Is it possible for an aircraft propeller to become supersonic? I am not referring as for the aircraft, only the rotating blade. I know it is extremely unlikely for a propeller plane to go supersonic, ...
Dody Him's user avatar
0 votes
1 answer
104 views

How many ways/methods to calculate propeller/rotor's power output? Which one is the best?

Source: Wikipedia I want to know how many ways/methods to calculate the output power of a propeller? So far I knew three methods: Momentum Theory (MT), Blade Element Theory (BET), Blade Element ...
AirCraft Lover's user avatar
-1 votes
1 answer
378 views

What velocity is used to calculate maximum range and maximum endurance?

These are my data; $C_{L_0} = 0.4$ $C_{L_{\alpha}} = 5.7$ $C_{L_{minD}} = 0.14$ $C_{D_{min}} = 0.022$ $k = 0.035$ $\alpha_{stall} = 15$ $S_{ref} = 20m^2$ Mass Data $W_{total} = 2500 \text{ kg}$ $W_{...
Bugra's user avatar
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1 vote
1 answer
86 views

XRotor blade angle distribution

My question is about the XRotor definition of the blade angle distribution (beta), which XRotor solves for or requires as input. Is the blade angle on XRotor defined as the angle between the rotation ...
Dionysis Rouvas's user avatar
2 votes
1 answer
170 views

Do full-feathering constant-speed propellers have a high-pitch stop for the prop governor?

On full-feathering (hydraulic) constant speed propellers in general, and specifically Hartzell and McCauley props, does the propeller governor have a high-pitch stop (like non-feathering propellers, ...
TheEagle's user avatar
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1 vote
4 answers
235 views

Should I advance my propeller lever forward during a glide?

I am reading the FAA Airplane Flying Handbook, chapter 3. It says: To enter a glide, the pilot should close the throttle and, if equipped, advance the propeller lever forward. (...) Why do we ...
Hitomhi's user avatar
  • 349
3 votes
3 answers
525 views

Cause of Drag From Windmilling

I know that when a propeller is windmilling it creates drag, I assume this is from the propeller being flat against the air causes drag, but propellers are designed to essentially pull an airplane ...
BryBuriya's user avatar
  • 307
2 votes
1 answer
196 views

Can a propeller with 90° pitching and symmetrical airfoils generate thrust?

Imagine we have a plane that is already moving at a speed $v_{plane}$. At a certain time $t=0$, a motor starts moving a propeller whose blades consist on symmetrical airfoils with $90^\circ$ of ...
user3141592's user avatar
2 votes
1 answer
179 views

Actual non-axial airflow (sideslip) for a propeller driven aircraft

I am making a propeller model for a two-engine propeller driven aircraft (like a Dornier 228). I have expanded my model to include the non-axial airflow as well. $$ $$ By non axial airflow, I mean ...
Neelabh Jyoti Saharia's user avatar
1 vote
2 answers
137 views

Does the obstruction in a propeller duct increase exhaust pressure or decrease pressure/increase speed?

I came up with this question when looking through the answer for this question, which states that a convergent duct(obstruction) compresses the exhaust so that its pressure matches the ambient ...
Frank's user avatar
  • 415
8 votes
1 answer
963 views

Are there any variable-diameter propellers?

Have there been any known tests or prototypes of variable-diameter propellers? There's this paywalled paper from 2014 that seems to have made a virtual prototype model, have there been any physical ...
user avatar
8 votes
4 answers
4k views

Can you weld a propeller blade from 120 degrees to 180?

My uncle flew for Mission Aviation Fellowship (maf.org) for a university in Texas, and I believe that he was flying a Cessna to the Amazon (among other places). He actually knew Jim Elliot (who went ...
MicroservicesOnDDD's user avatar
6 votes
1 answer
259 views

Could floppy rotor blades be usable?

Autogyro and helicopter blades are more or less flexible, and when not stiffened by centrifugal force they droop noticeably. A extreme case would be that of fabric blades. They have been used at least ...
xxavier's user avatar
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14 votes
1 answer
2k views

What is this indication on most turboprops?

What is the small fan I've seen on different turboprops?
Boeing787's user avatar
  • 6,454
0 votes
1 answer
600 views

Why would the tip of a propeller stall if geometric pitch was the same throughout the length of the propeller?

I can't seem to understand this sentence from the FAA PHAK about why propellers are "twisted." "If the blades had the same geometric pitch throughout their lengths, at cruise speed the ...
thunderstormies's user avatar
9 votes
3 answers
2k views

Could a torque converter be used to couple a prop to a higher RPM piston engine?

Every RPM reduction gearbox I look at seems to have more parts in it than a Swiss watch. Great for keeping time but many parts to wear and breakdown. What seems especially worrisome is the direct ...
Robert DiGiovanni's user avatar
3 votes
2 answers
959 views

Why are aircraft piston engines are so low rpm lazy engines?

I understand that the propeller speed should not be too much otherwise it will stall at the tip and be useless so higher rpm engine would be useless when we first think about it. However, we can put a ...
Timothy Scherer's user avatar
0 votes
1 answer
88 views

Stall on low airspeed with high power on right-turning propeller

Q: The pilot of an aeroplane with a single engine and right-turning propeller (clockwise from the pilot’s viewpoint) decides to go around. The pilot raises the nose too much as the power increases and ...
Filip Adam's user avatar
2 votes
2 answers
160 views

Torque and engine torque after aplying prandtl tip loss factor

I have a question regards to the following formula related to Blade Element Momentum theory for the application to calculate on airplane propellers: $$ dQ=4\pi r^3 \rho V_\infty(1+a) a' \Omega F dr ...
Veltro's user avatar
  • 65
1 vote
1 answer
702 views

How to know what kinds of airfoil being used in a commercial propeller?

Suppose we know the 3D CAD model of a commercial propeller. Starting from that, we do the slicing to get the profile of airfoil being used to generate the complete shape of the propeller. How do we ...
IFX21's user avatar
  • 11
2 votes
1 answer
218 views

What would have been the pitch angle of this McCauley Prop before impact?

I'm trying to determine the pre-impact pitch of a two blade McCauley variable pitch on a Cessna 210 that hit shallow ocean water (8 feet, mostly sand) shortly after takeoff from an altitude of 300 ...
Argonaut5's user avatar
2 votes
2 answers
744 views

How does propeller length, pitch, and airspeed affect efficiency? [closed]

tl;dr: trying to find propeller efficiency with thrust, velocity and power and see which propeller length to pitch ratio is efficient. Hello, I'm a high school student working on an extended essay for ...
shrey's user avatar
  • 21
2 votes
2 answers
2k views

What is the nature of feathering in an ATR type aircraft?

If the engines fail for some reason midflight, does the ATR aircraft automatically feather the affected engine? In rare cases if both engines fail, does the automatic feathering happen for both ...
Regmi's user avatar
  • 925
0 votes
2 answers
309 views

Centrifugal force created by a 1045 propeller

I currently am creating a project in which I'm using a 1045 propeller with a BLDC motor that spins at ~16,000RPM. It is powering a single motor "rocket" that basically is configured to carry ...
Aadiraj Anil's user avatar
1 vote
1 answer
206 views

P Factor vs Spiral Slipstream

Does anyone know of any real aeroplane or wind-tunnel tests that quantifies the effects of asymmetric propeller blade loading (P factor) versus the Spiralling Slipstream effect in creating yaw. Which ...
Forbes's user avatar
  • 319
-2 votes
2 answers
552 views

Is my equation for calculating ducted propeller thrust correct?

The equation is 13(EfficiencyxProp diameterxoutlet diameter)^2/3 It seems really high when I use inches and really low when I use feet.
Lelotz's user avatar
  • 127
11 votes
4 answers
2k views

If the pitch of a bypass fan blade in a turbofan is fixed how does it manage to provide thrust over such a large speed range?

A fixed pitch propeller is only good for aircraft that do around 100kts because the angle of attack on the propeller decreases as the forward airspeed of the aircraft increases, limiting the thrust ...
Ian's user avatar
  • 111
1 vote
0 answers
99 views

Would the dle 55ra engine be enough to power my paramotor(ducted fan)?

I plan on using the dle 55ra engine to produce 5hp at 8,500 rpm. I am using it in a paramotor, and to save space I am considering using a ducted propeller similar to the Fulcrum power pod. The duct ...
Lelotz's user avatar
  • 127
24 votes
4 answers
7k views

How did the propellers on the B-29 stop perfectly in sync?

In the photos below, the propellers on the B-29 props all stop in the same position. Is this done by hand, it is this automatic?
Boeing787's user avatar
  • 6,454
3 votes
1 answer
190 views

What is the aerodynamic influence of prop spacing and placement in multi-prop engine setups

I saw this question Is there a rule of thumb for spacing between jet engines?, which referred to How do you choose engine placement for under wings engines?, but I was wondering how the engine spacing ...
ROIMaison's user avatar
  • 7,367
0 votes
0 answers
108 views

where is the centrifugal force the flyweights experience coming from?

The T6b uses a PT6-68 engine which has a variable pitch, constant speed, feather, and non-reversible prop system. There is only one lever in the cockpit which regulates Torque and the Power Management ...
YamchaAviator's user avatar
1 vote
2 answers
968 views

How to calculate lift/thrust effect of adding blade to a propeller?

Source: Say I have blades of a propeller of an aircraft (airplane or helicopter). The blades have exactly the same profile, size, dimension, and weight, and will be coupled to a shaft with the same ...
AirCraft Lover's user avatar
0 votes
1 answer
62 views

Has the use of a radiator surface on the inside of duct ever been tried?

I wonder if using radiating surface on the inside of a ducted fan to dispel the waste heat of an engine would provide an economic advantage by increasing thrust? Since a typical engine “wastes” some ...
Numpty One's user avatar
3 votes
5 answers
618 views

Estimating piston-engine thrust on take-off

In my Uni course I've learnt how a piston-engine produces a constant power, as opposed to a constant thrust like in a jet engine, which can be estimated as Thrust = Power / Velocity. However, using ...
Joe Franks's user avatar

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