Skip to main content

Questions tagged [blade]

Use for a gas turbine's, propeller's, or rotorcraft's blades

Filter by
Sorted by
Tagged with
19 votes
2 answers
24k views

Why are aircraft turbine blades made of nickel alloys?

Why are aircraft turbine blades made of nickel alloys? What is the advantage of using them? Why did they replace steel alloys for turbine blades? How to overcome failure cases of turbine blades?
user8325's user avatar
  • 191
7 votes
3 answers
12k views

Why don't helicopters prefer shorter rotors with more blades? [duplicate]

My understanding of helicopters is that, despite theoretically increasing efficiency, longer blades are worse in practice than short ones in every respect (except, perhaps, cost): Longer blades are ...
feetwet's user avatar
  • 2,284
5 votes
3 answers
4k views

How does the relative wind on a propeller, strike the blade from behind (the non camber side)?

This may be a stupid or simple question, although any help is appreciated! :) If possible, please answer without mathematical terminology. So I understand the concept of the blade increasing air ...
ApolloMission4's user avatar
23 votes
1 answer
7k views

Can you identify this jet turbine stage?

I was just wondering if anyone could give me any info about this turbine rotating stage I picked up at a yard sale today. The stage measures 8-1/2" to the outside of the blades. The only markings I ...
Jason Freier's user avatar
6 votes
1 answer
4k views

What is the fan tip speed at maximum thrust?

What is the fan tip speed at maximum thrust? Is it any different for a Rolls-Royce Trent 900 (powers the Airbus A380) and Pratt & Whitney PW6000 (powers the Airbus A318)? Are they efficient at ...
securitydude5's user avatar
4 votes
2 answers
662 views

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 ...
FZ123's user avatar
  • 75
32 votes
4 answers
13k views

Why are the fan blades mounted loosely?

In this question it is mentioned that the fan, compressor and turbine blades are mounted loosely in the disc. This is well demonstrated by this video posted by RedGrittyBrick. What is the reason for ...
TomMcW's user avatar
  • 28.6k
5 votes
3 answers
3k views

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 ...
user19440's user avatar
  • 1,075
0 votes
1 answer
501 views

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 ...
Paul P.'s user avatar
  • 21
23 votes
1 answer
3k views

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 ...
DrZ214's user avatar
  • 17.8k
8 votes
1 answer
459 views

Are engine casings expected to contain turbofan blade fragments?

On Southwest 1380, initial indications are that a fragment of the engine blade pierced the engine casing, which then hit the airplane window (or perhaps a part of the casing did). According to the BBC,...
adam.baker's user avatar
7 votes
5 answers
15k views

Why do jet engine fan blades have a twisted shape?

I'm thinking: as the blades rotate, the tip moves faster than the hub. So to make the blades efficient, the blades are usually twisted. The angle of attack of the blades at the tip is lower than at ...
D. Frederico's user avatar
5 votes
3 answers
7k views

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 ...
Gerry's user avatar
  • 848
4 votes
1 answer
962 views

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? ...
Arie's user avatar
  • 117
4 votes
1 answer
2k views

What is the longevity and replacement schedule for turbine engine blades?

I'm trying to understand how frequently hot section turbine engine blades are changed out. Is this a calculation based on flight hours, material, engine size or maybe something else? Apologies if ...
Scott's user avatar
  • 73
4 votes
3 answers
1k views

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? ...
Aviation Enthusiast's user avatar
4 votes
2 answers
4k views

Is it possible to get a list of Cl/Cd values for various NACA Airfoils?

There are a lot of links which give the shape of the airfoil for any given set of camber thickness, position and max. thickness values, but I would like to know if it is possible to get the Lift vs. ...
Manish's user avatar
  • 569
4 votes
3 answers
331 views

How to estimate blade interference in a propeller or fan?

The ideal propeller has one blade. For obvious reasons, that would be impractical. However, adding more blades causes each blade to operate in each others slipstream/downwash. How to quantitatively ...
toshi ba's user avatar
  • 411
3 votes
3 answers
4k views

What is the correct equation for rotor solidity?

I'm working in a project that uses"blade solidity ratio", or "rotor solidity", the problem is, there are several articles which defines the equation in a different way changing in the section of the ...
Resou's user avatar
  • 31
1 vote
1 answer
383 views

What causes a helicopter to autorotate farther?

Which characteristics improve a helicopters ability to glide a farther distance in autorotation? Do these same characteristics reduce minimum decent speed in autorotation or is that affected ...
Muze's user avatar
  • 1
1 vote
2 answers
1k 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
436 views

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 ...
Eaza's user avatar
  • 121
0 votes
1 answer
2k views

Is low pressure compressor air used to cool turbine blades?

This photo shows LP cooling air is being used to cool turbine blades. the question is, is it possible to use LP air to cool the turbine blades? would you please guys explain why do they use LP air ...
5A-ALI's user avatar
  • 33