Questions tagged [blade]
Use for a gas turbine's, propeller's, or rotorcraft's blades
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What aircraft has the propeller with the highest blade count?
Among all known propeller (unducted) aircraft, which one has the highest number of blades?
Experimental aircraft also count.
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What is the relationship between Angle of Attack and Induced Flow?
(Image Source: Principles of flight. ATPL ground training series - Author: CAE Oxford Aviation Academy (UK) Limited 2014)
I'm studying the airplane's propeller. And I found this picture in my ...
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Hoping to get some details on the GE CF6-50 Turbine bucket thermal protective coating
I just bought this beautiful little bucket and am trying to find the details so I can describe it accurately.
Just based on the gold appearance I assumed it was TiN, but looking further it seems like ...
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Is blade flapping "fully automatic"?
I have a rather simple question just to "double check" if I understood blade flapping right. So, I understand that a helicopter, in forward flight faces an asymmetric lift. Blade flapping is ...
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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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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 ...
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Why phase lag on helicopter blade is sometimes 90°, and sometimes less?
On semi rigid rotor head, phase lag is 90°, and also the advance angle between pitch link and coresponding blade. But of fully articulated rotor the phase lag is less then 90°, and also the advance ...
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Helicopter blades flapping with the cyclic – can you help with the explanation?
I am now reading books about helicopter aerodynamics. And I have one question about blades flapping.
If you push forward on the cyclic, the swashplate will tilt forward and will set the maximum pitch ...
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Authorization of repairing engine blade nicks
Since blade nicks repair considered as a major repair, I would like to ask,
1- Who is authorized to repair engine blade nicks?
2- Could a mechanic with powerplant rating do the repair?
3- Could a ...
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Turbofan engine fan blade leading edge fairing?
A lot of aircrafts feature a leading edge fairing for the wing, at the connection with fuselage, in order to reduce the airflow interference.
Aerodynamically speaking, those fan blades in the turbofan ...
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How to plot figure of merit vs blade loading coefficient for helicopter rotor?
I know the formula of figure of merit and blade loading coefficient individually but how the plot can be obtained I am not getting that. What would be the formula for figure of merit in terms of blade ...
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Sensors used on a blade
How to measure the strain, temperature and rotational dynamics on a running engine fan blade? How can you do the experiment?
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Why does the helicopter Robinson R22's rotor blade have flat part as in the picture? What is it for?
Picture source:
Picture source:
This is Robinson Helicopter R22's rotor's blade. What is this flat part for as indicated by the red line? What is the aerodynamic benefit of putting it? There are many ...
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What airfoil can be used in making a turbofan engine fan blade? [duplicate]
The thing is, I am trying to make turbofan blades in Solidworks for a possible undergraduate thesis. I would like to know if there is any airfoil from the NACA series or anything plausible for this ...
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What airfoil family does turbofan's fan blades use?
The thing is, I am trying to make turbofan blades in Solidworks for a possible undergraduate thesis.
I want to know if there is any airfoil from the NACA series or any airfoil families plausible for ...
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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 ...
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Why can the rear rotors of helicopters move freely in this direction?
As you can see in the video in the imgur link below i recorded a video of the Alouette 2 rear tail rotor and as you can see it moves freely in that direction. Why does it freely move in that ...
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There is any kind of advantage and disadvantages in making the blades of a helicopter off-center?
So, english isn't my first language, so I probably couldn't find any kind of information about it due to not being able to define what I'm asking.
Anyway, helicopter blades are normally like this:
An ...
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Why do some jet engines have fewer fan blades than others?
I have found out upon researching jet engine fan blades that they can vary from 16 to 34. Why do they vary, I mean, does decreasing or increasing the number of fan blades have any performance impact? ...
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From which jet engine is this blade?
Some years ago I bought a compressor blade on ebay but I don't know which jet engine it's from.
It's quite light. I tried to determine the density by the help of my kitchen equipment and it's most ...
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What causes ram air turbines with more blades to spin slower than turbines with two blades? [closed]
Lets say aircraft has two ram air turbines that work as generators to produce electricity on each wing. One has two blades and one has 8 blades, both with the same diameter.
What is the aerodynamic ...
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What are the design principles that result in thin, long-span, narrow chord main rotor blades?
Regardless of the overall design configuration of a helicopter, it appears that helicopters have main rotor blades that all fall into the class of ultrahigh aspect-ratio wing design: that is, you ...
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There is any example/studies/concepts on really short blade jet turbines/turboshafts? [closed]
Well, from the little I know, I think the reason jet turbines can't go that fast is because the tip of the blades would reach supersonic speeds and starting to generate too much drag.
However, if, for ...
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What is the function of the aft stator in CFM's open rotor engine design?
CFM revealed their design for a open rotor propfan engine with two stages of blades - one active set of blades rotating in the forward and an static sets of blades on the aft.
According to The ...
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What are those ball-shaped things on some helicopter blades?
I saw these things swinging in a video of a rotor from the blade point of view. I don't know what are they for but I am quite curious. And why some helicopters have it and some don't?
Source: alamy
...
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In constant speed propeller, if i increase RPM lever from 2300 to 2500, will the Blade AOA decrease?
Assume I am flying straight and level with power setting 21 inches of MAP and 2300 RPM with TAS=100 kts, now I change my Prop lever only (MAP = no change & TAS = no change) from 2300 to 2500, ...
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Is pitch-flap coupling an aerodynamic effect or an intrinsic property of a delta 3 offset?
I am modelling a propeller, in particularly the equations of motion of the various pitch/lag/flap angles as the propeller is turning around. The blade includes a $\delta_3$ angle, which provides pitch-...
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Helicopter mast bumping in low g condition
The helicopter shown in the concrete pouring video seems to taking off from a hill and descending down in a way which can be classified as low G with low rotor loading. Although, the helicopter is ...
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What other materials apart from conventional nickel and steel superalloys can be used as a first stage turbine blade material?
Steel and nickel chromium alloys have been prominent and most used as turbine blade material although there are other materials such as tantalum carbides, tungsten and many more which I have no ...
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Why are jet engine fan blades painted?
I came across this extremely interesting article with details on a 2018 United Airlines Boeing 777 engine failure, which is also related to the more widely-publicized failure a few days ago: http://...
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Retreating Blade Stall, P-Factor, and Gyroscopic Precession
Most airplane pilots are aware of P-Factor in propeller driven aircraft and that it tends create a torque in phase with the lift imbalance over the blade disc, resulting in a yaw moment about the ...
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How much weight does a blisk save?
A Blisk is a bladed-disk, all one monocoque component.
So the blades do not have to be inserted and secured, and they are not removable. No nuts and bolts either.
The downside is that any serious ...
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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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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 ...
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How the pitch of a blade must change along the length so that the blade does not stall?
I have to finish an assignment in the next couple of days. One of the questions asks to show how the pitch of the blade must change along the length so that the blade does not stall. I have no idea ...
user54043
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What are these painted lines on the fan blades of the Rolls-Royce Pearl 15?
I'm not sure that they are painted but it looks like they are. What are they for?
More images:
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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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Why do new helicopters have rotor blades with swept tip? [duplicate]
Many new helicopers have rotor blades with swept tip. Why? Acoustic? e.g.
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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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What is the most recent turbofan engine that used steel for its bypass fan blades?
I haven't been able to locate any engines that use steel for the bypass fan. All sources suggest Ti and composites are used for blade construction. Apart from the weight steel could partially make up ...
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Helicopter Basics: How does lead-lag of blades actually help in compensating for increase/decrease in speed due to flapping?
I understand the following -
Due to dissymmetry of lift, flapping up and down occurs.
Since angular momentum has to be conserved, the speed of blade increases/decreases during flapping
up/down ...
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How accurate is XFoil / XFLR5 at 'kinda high' Reynolds numbers?
How accurate is XFoil/XFLR5 at Reynolds numbers between 2 million and 10 million?
From my understanding it's only accurate at lower Re values.
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What is a compressor cascade?
Is a compressor cascade just the representation of the blade ring of an actual turbomachine? What is the difference between linear cascade and annular cascade? A diagram or a reference would be great.
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Why does each fan blade have a different mass and frequency?
From a documentary (at 16:39) on building a Rolls-Royce jet engine:
... no two finished blades are exactly alike, and with twenty in each fan, it will only spin smoothly if the blades are perfectly ...
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How to calculate the number of blades?
Inspired by building a new drone, I got lost in curiosity.
What if I have a fixed length of rotor blades and a target amount of lift I want to, well, lift. How do you calculate the number of blades?
...
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How does increasing the RPM result in a higher AOA for the blades?
I know that an increase in velocity (TAS) reduces the AOA and that makes sense. But how just simply increasing the blade rotation (RPM) results in higher AOA?
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How does a Delta-3 hinge on a helicopter tail rotor work?
I am trying to understand how adding offset hinges would provide a self-feathering force. Does anyone have more information on Delta hinges on helicopters? I am a bit confused with the information I ...
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Could a shrouded fan blade with long chord length be efficient?
I am wondering if it would work to have a fan with two or three blades which have short-ish span and very long chord length, like half a rotation for each blade. Would a shroud (that is molded on the ...
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How often are turbine blades in jet engines replaced?
How often are the turbines in the hot section of the jet engines replaced due to deteriorated TBC? or just how often are they replaced? lets say for CFM56-7
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How to calculate the moment/torque at the center axis of a blade?
How do I calculate the moment/torque at the center axis (same plane with lift and drag force) of a blade with NACA airfoil standard when it is placed inside a wind tunnel or exposed to airflow?
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