# 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....
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### 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 ...
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### 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 ...
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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 ...
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### 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/...
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### 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 ...
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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 ...
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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 ...
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### 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 ...
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### 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 ...
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### 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 ...
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### 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 ...
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### 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 ...
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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
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### 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 ...
1 vote
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### 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 ...
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### 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 ...
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### 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, ...
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### 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 ...
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### 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 ...
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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?
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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 ...
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### 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, ...
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### 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 ...
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### 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 ...
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### 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 ...
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### 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 ...
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### 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 ...
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### 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 ...
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### 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 ...
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