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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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2answers
368 views

Would a coaxial propeller with the second prop slower and larger improve speed?

Looking at various propeller designs, I started wondering about these limitations: Large propellers at high speeds have tips going supersonic Scimitar props attempt to keep prop tip from going ...
3
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1answer
170 views

If a twin-engine airplane's propellers both rotate in the same direction, do they still produce a left-turning tendency?

If an airplane with two propellers has both propellers with the same rotation direction (say, both the propellers rotate counter-clockwise as seen from nose to the tail), will be the four left-...
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1answer
93 views

Where can I find info or techniques on calculating the influence of a duct on the thrust and efficiency of a propeller?

I am trying to run numbers on a concept VTOL fixed-wing aircraft, and I am looking at having fans or props positioned inside the wings, (which would therefore make the wings relatively thick for a ...
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1answer
58 views

How can I calculate the velocity of air drawn by a pusher configured propeller?

I am attempting to construct a model plane using Custer channel wings. In order to calculate (or at least approximate) the lift generated I need to find the speed of the air through the channel due to ...
3
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0answers
255 views

How are the Tupolev Tu-95's blades shaped?

The Tupolev Tu-95 "Bear" seems like an awfully cool piece of innovation with its unusual contra-rotating supersonic-tipped props. From what I've been reading it sounds like it's been the only mass ...
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0answers
271 views

What contra-rotating propellers would be appropriate for this engine?

I am currently getting an X4 cylinder, 150cc, 4 stroke engine 3D CAD Modelled, this engine is initially being designed for Powered Paragliding (PPG), classified as experimental Aircraft, so no ...
2
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0answers
225 views

Is this equation for propeller thrust correct?

From dimensional considerations, and assuming that the power $P$ applied to a propeller of diameter $D$ moving at an axial speed $V$ is 100% converted to the acceleration of a mass of air with density ...
2
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0answers
218 views

What calculations are needed for counter-weight balancing on a propeller?

I am designing a small-scale propeller and i have managed to design on optimized geometry for the blade. However the blade pitch angle adjusts according to different flow speeds so i need to mount ...
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0answers
168 views

Could this propeller work on a quadcopter and decrease the sound?

I came across a video yesterday that showcased a propeller design that looked very interesting. I am a regular drone flyer and I constantly look for exciting things to try out. Would this design in ...
2
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0answers
282 views

Can quadcopter-like UAVs ever get significantly quieter? Any candidate technology?

The light weight quadcopter and hexacopter UAVs that can cary say 2kg to 20kg payloads for "delivery" produce enough noise that a steady stream of pizza and book deliveries might not be so welcome in ...
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0answers
40 views

Does Froude Efficiency represent an upper bound for propellers in certain flight / aircraft conditions?

I used the Simple Propeller Theory to calculate the Froude Efficiency for my theoretical propeller-driven craft (at 65k feet). Here are the results: https://ibb.co/kPPqzU. My results were that, for ...
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100 views

How does a partially covered air intake affect the thrust of a propeller ?

does a partially covered air intake of a ducted propeller significantly affect its thrust? If so, will it be like 10 or rather 90 percent less thrust ? Thanks for your answers! Simon
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0answers
172 views

What Inertial effects should be considered to achieve blade stability on a Variable Pitch Propeller tailoredby aerodynamic loads?

I am developing a self adjusting variable pitch propeller tailored by its pitching moments due to aerodynamic loads setting the blade rotation axis in an offset from the aerodynamic center as shown ...
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0answers
157 views

What causes these losses in this propeller simulation?

While running a CFD simulation comparison of 2 vs 3 blade propeller versions (48" diameter, 23" pitch, 3570RPM), I've come up with: 2-blade: 347N of static thrust @ 110Nm Torque 3-blade: 220N of ...
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0answers
192 views

What is the history of this specific Cessna propeller (s/n F2430)?

Hoping someone can help... I'm looking to get some information about a Cessna plane propeller my Fiancé recently bought. It's his birthday coming up and it would be great to have any sort of history, ...
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0answers
66 views

How can I use electric motor data with my prop data to obtain a power available verses velocity curve?

I'm not entirely sure this is appropriate for this forum but it's worth a shot... I have propeller data ($C_T$ , $C_P$ , J , and $\eta$) and very very limited electric brushless motor data (motor ...
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0answers
52 views

flow rate through a propeller disc

Let's take the case of a stock Cessna 150, chained to the ground, standard day conditions. The engine is running at full power (say 2500RPM) and the propeller is absorbing its full output. Is there a ...
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0answers
43 views

How to compute actuator torque requirement for Variable pitch mechanism??

Suggest me any reference to compute the torque requirement for actuator/motor to control the pitch angle of propeller (Variable Pitch Propeller). Thanks in advance Arun Ravindran
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0answers
78 views

Propeller air displacement

I was thinking about propeller design just now and it came to mind that, theoretically, the air displaced by the propeller after every rotation might not be able to "flow back" into the area "served" ...
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0answers
24 views

How to properly estimate induced flow

Good day. I am currently in a group that is projecting a rotor that when launched must enter in autorotation. The estimated velocity of descent is $V_z=1.29$ $m/s$ which is approximately the same ...
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0answers
161 views

What is the relationship between speed, torque and pitch in a helicopter?

Can someone clarify the relationship between aircraft speed, torque, prop length and pitch and how this applies to a helicopter. In addition I want to know if the amount of lift a helicopter ...
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0answers
544 views

why are airplane propellers always undersized?

While calculating propeller static thrust by using a famous Prop-power-calculator.xls (by Pé Reivers), I've noticed that no matter what "stock" configuration I put into the calculator, I do always get ...