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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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Are narrow propellers more efficient than wider ones?

I came across this company E-Props that builds propellers and it seems like all their propellers are narrower, at least narrower than traditional ones I'm used to see, and I see on their picture ...
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Terminology for sounds of the helicopter 🚁 [closed]

Deep Breath! I am not a pilot, but KNEW to join and ask you/ this group! 1.I dreamt this last night. 07/ 07/2024; and the last scene of this INTENSE Dream from GOD was: A wave of our Military's (U.S....
Nicole Ramirez's user avatar
1 vote
2 answers
108 views

Propeller Torque Calculation

Propeller torque is given as $Torque = c_p * ρ * (\frac{ω}{2π})^2 * d_p^5$, where $c_p$ is the torque coefficient, ρ is the air density, ω is the angular velocity, and d is the propeller diameter. I ...
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Is there a convention of propeller tip separation from the wind tunnel walls?

Blockage ratio is commonly used to address the effect of confinement on the propeller's performance tested inside a closed test section of a wind tunnel. In most cases, blockage corrections (like ...
Ahmed's user avatar
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7 votes
2 answers
590 views

How to calculate velocity of air behind a propeller?

Background: I came across this article by Gabriel Staples to calculate static and dynamic thrust of a propeller. In the derivation, it was assumed that the exit velocity is equal to the pitch speed of ...
NeelD's user avatar
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1 answer
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Three-blade propeller balancing

I'm balancing a three-blade propeller. The propellers weigh exactly the same to the 10th of a gram. When I place it on shaft with a very sensitive wheel bearing, one of the blades always moved ...
Ricardo Zelaya's user avatar
1 vote
1 answer
67 views

McCauley propeller models IC235/LFA7570 and IA170E/JHA7660

I am writing to inquire about the pitch specifications for the following McCauley propeller models: IC235/LFA7570 with a maximum diameter of 75 inches and minimum diameter of 74 inches. IA170E/...
rafael rosolen's user avatar
5 votes
2 answers
202 views

Could a propeller system for airplanes with automatic, cyclic blade-pitch control that is designed to counter p-factor be practical?

Considering that P-factor is a result of differing angles of attack of the blades on an airplane's propeller, I would imagine that if there was a design that could control the pitch of each individual ...
Ryan Mortensen's user avatar
5 votes
3 answers
141 views

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
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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
146 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
178 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
175 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
170 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
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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
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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
267 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
61 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
134 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
104 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
178 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
212 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
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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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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
668 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
110 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
399 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
91 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
197 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
267 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
540 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
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2 votes
1 answer
199 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
180 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
138 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
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8 votes
1 answer
973 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
262 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
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0 votes
1 answer
697 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
1k 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
95 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
169 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
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1 vote
1 answer
807 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
228 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
862 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
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1 vote
2 answers
335 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
229 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
635 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
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