Questions tagged [thrust]
Questions about the propulsive force of a winged airplane.
10
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9answers
3k views
Can hydrogen gas be an alternative fuel source for a gas turbine engine?
I want to do research for an alternative fuel source for a commercial aircraft that will reduce the cost for flights.
Will the hydrogen gas be ignited in the combustion chamber and produce enough ...
-1
votes
1answer
126 views
Which propeller configuration is the one that generates the least turbulent flow in a wind tunnel?
I looked at the post here but still have some questions Why are push-propellers so rare, yet they are still around?
This is along the same idea but the answers are not too helpful either. Pros and ...
16
votes
2answers
4k views
What does it mean to “firewall” an aircraft engine?
I (think) I understand what a firewall is (at least, in a single engine aircraft where the engine is at the front of the fuselage), but what does it mean "to firewall" an aircraft's engines, as ...
0
votes
2answers
69 views
How to calculate power required to drive an isolated fan of a TurboFan engine?
If I isolate the fan from a TurboFan jet engine (specifically GE90) and power it electrically with a motor,
how much power is required for the electrical source to drive the fan to give the same ...
0
votes
2answers
60 views
What's the thrust coefficient for a convergent nozzle?
As you know, the Ideal Thrust Coefficient of convergent-divergent nozzle is calculated using this equation:
But what about a convegent nozzle? Is there any equation to calculate the Ideal Thrust ...
1
vote
1answer
321 views
How do I determine the engine thrust required to give a specific climb rate?
New pilot here and I am playing around with a flight simulator game for the B737-800. I need some help understanding where/how one can find out if one has enough engine thrust (%N1) to meet a required ...
1
vote
2answers
371 views
How does the line of thrust affect longitudinal stability?
I’ve been studying Pilots Handbook of Aeronautical Knowledge FAA-H-8083-25B and on p 5-17 they talk about thrust line and stability. Can someone explain why the moment changes when thrust is applied?
...
-1
votes
1answer
193 views
What are the Boeing 777 thrust calculations? [closed]
Can someone show typical calculations for a Boeing 777 jet engine for the following criteria:
Take off thrust of the engine at 170 mph take off speed and 45 degrees F
Cruising thrust required at 500 ...
3
votes
2answers
144 views
Can lift be equated to how much air is moved?
The explanation for lift that I find easiest to visualize is that air is deflected downward by the wing. This downward action causes an equal and opposite reaction of an upward force against the plane,...
0
votes
2answers
95 views
How does radius of a propeller affect its performance?
Let's say we have a conventional two-bladed fixed-pitch propeller. All things being equal, would the same propeller but with half the size -- 50% radius, have 50% of the performance of the first ...
0
votes
0answers
68 views
How does the number of blades affect the static thrust of a propeller? [duplicate]
Since I couldn‘t find an answer to this question I thought I‘d ask you guys!
By which factor does the thrust of a propeller increase if I double the number of blades, the motor being powerful enough ...
5
votes
2answers
811 views
Is 1 propeller always more efficient than 2?
Based on other answers I've read here (1) (2) (3), a single large blade propeller is the most efficient type of thrust you can get.
There are 2 reasons for this (as I understand it). Firstly, ...
3
votes
1answer
199 views
On a ducted propeller, how does duct length affect thrust?
So if we are looking at an aircraft with a ducted propeller (or a high bypass turbofan engine), does it matter how long the duct is? As an extreme example, would having a duct that extends 100 feet ...
3
votes
5answers
336 views
How do thrust reversers in high-bypass turbofan engines counteract initial thrust?
I've been searching the internet for awhile and haven't really come across a good answer for this question. So:
I have a basic understanding of the principles of flight (thrust, lift, drag, etc). But ...
0
votes
0answers
33 views
How turbofan engine efficiency increases over altitude or speed? [duplicate]
I am confused a lot about the efficiency and thrust relation with altitude and velocity of an aircraft. If thrust is related to air mass flow and velocity diffrence of bypassed air - exhaust gases ...
2
votes
1answer
915 views
Is it best to use a thick airfoil or an undercambered airfoil for slow speed flight?
The more the thickness,the more the frontal resistance,hence the more the drag a thick airfoil will produce.
Under cambered can help increase lift without increasing the airfoil thickness , therefore ...
2
votes
2answers
815 views
Why does the diffuser section generate thrust in a jet engine?
I am studying the thrust distribution of jet engines.
But I'm now a bit confused.
In Rolls-Royce's "The Jet Engine" book,
http://aeromodelbasic.blogspot.com/2012/05/thrust-distribution-distribution-...
6
votes
2answers
193 views
How do engine manufacturers derive varying amounts of thrust from a single engine model?
What changes do manufacturers make to an engine to vary the amount of thrust it produces for different applications? Take the GE CF34 for example where there is a 10780lb difference between the thrust ...
1
vote
1answer
323 views
What creates most drag during flight: fuselage or wings?
From pic 1, I know the drag line is below the thrust line, but I am puzzled about where the drag line is in pic 2?
Secondly, what creates most of the drag in flight, is it the fuselage or the wings?
-1
votes
1answer
542 views
How much air does a GE90 ingest at sea level and at cruise level per meter?
I just wanted to know how much air PER METER a GE90 turbofan engine sucks in considering the same thrust output at different altitudes to better understand how the engine can travel further while ...
0
votes
7answers
787 views
Is it possible to fly 'in neutral'?
Sometimes, when I am driving, I knock the car 'out of gear' or set the stick to the neutral position, to save fuel. This is most easily done when cruising down a hill or when you have some good speed ...
1
vote
2answers
145 views
Mach Factor - Factor increase of thrust due to the ram effect
In the book of Corke, Chapter 7 about engine selection, he speaks about the Mach factor which is a factor larger than 1 in supersonic to take into account the ram effect.
In his case study he takes 2,...
2
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2answers
559 views
Pros and cons of a pull-push propeller configuration [closed]
What are the pros and cons of a pull push propeller in comparison to a counter rotating propeller?
3
votes
2answers
762 views
How to realistically model propeller static thrust?
I am graphing static thrust vs prop diameter for a 600 kW motor and a prop diameter up to 5 m. I have seen the post 'What is the equation for calculating static thrust?' and using its formula and ...
6
votes
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 ...
14
votes
7answers
6k views
How do rocket engines produce more thrust than aircraft jet engines?
I can't find the reason why rockets are able to produce so much thrust when compared to turbojets.
I do know that the rockets carry their own own supply of oxygen since there is no oxygen in space or ...
25
votes
1answer
17k views
What provides the greatest thrust in a high-bypass turbofan engine?
I'll try to make as much sense as I can with this question.
I've been flying quite often in 2015, and I have recently wondered this question regarding high-bypass turbofan engines. I know that there ...
