Questions tagged [engine]
For general questions related to aircraft engines; use [tag:jet-engine] or [tag:piston-engine] if possible.
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1answer
93 views
How much does the swirl of engine exhaust affect aircraft performance?
Most multi-engine aircraft have engines that rotate the same direction on both sides of the fuselage (e.g. the GEnx rotates clockwise, as viewed from the front, there is no 'mirrored' version).
What ...
0
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1answer
89 views
Fuel De-aerating Tank?
I know turbine engines (bearings) are cooled by oil jets and that when oil is scavenged from the bearings it is more of a mist than a liquid, hence the need for various types of de-aerating this mist ...
3
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1answer
63 views
What is the standard for tachometer calibration / Hobb's equivalency?
I've heard that 1 tach hour = 1 Hobb's hour at maximum RPM. I've also heard that tach equivalency is at "cruise" RPM, although that seems vague.
I believe I've also heard that the accuracy of ...
1
vote
1answer
106 views
Why do pilots typically start out in piston-engined aircraft, rather than jets or turboprops? [duplicate]
Essentially all pilots begin flying with propeller aircraft powered by piston engines, rather than in turboprops or light jets, even though:
Operating a piston engine requires adjusting the mixture ...
4
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1answer
178 views
Why don't air-cooled radial engines use fuel to cool the oil?
Having read up on WWII air-cooled radials, one thing that struck me is how frequent is the mentioning of external oil cooler overheating, or the need for armored boxes around it, and some even venture ...
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0answers
50 views
What % of horsepower in a turbine is used by the compressor section?
If a turbine generates 10,000 shaft horsepower, I am trying to understand how much horsepower has been used to compress the air. So the turbine that generates 10,000 hp must in fact generate 10,000 ...
9
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3answers
2k views
Is the bleed air passengers breathe tapped from the engines before or after it comes in contact with fuel? And why? Isn't this unhealthy?
Passengers are often surprised to hear that the air they breathe comes from inside the engines.
This sounds unhealthy. Can you explain, why it is not ?
Is bleed air tapped (for cabin pressurization) ...
1
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2answers
141 views
Asymmetric thrust [closed]
Let's assume we lose left engine on a twin-engine aircraft during a straight and level flight without a side slip. In order to compensate yawing moment to the left from the right engine we deflect the ...
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5answers
226 views
I wonder if it's possible to make a “compressed air” turbine engine [closed]
I wonder if it's possible to make an efficient turbine engine that uses only hot compressed air to move but only that, meaning there is no ignition involved. To put it simple can we use compressors ...
1
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2answers
127 views
How many hours to remove and install a Cherokee 180 engine and prop
How many hours should it take a shop to remove, install, and adjust the engine in a Cherokee 180 with a fixed pitch prop?
This would include the baffles and any hardware needed to be removed and ...
0
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1answer
204 views
Do Military Turboshaft engines have a distinctly different sound from Civilian ones?
I live in India, and near an airbase so there are a moderate amount of helicopters flying overhead. My friend claims that he can distinguish between a civilian helicopter or a military one based on ...
82
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4answers
16k views
Why do we need to starve the engine before turning it off?
This question is for Piper Tomahawk, but I guess applies to any small aircraft.
Why do we need to use the fuel mixture to starve the engine before turning it off with the key? Why can't we just turn ...
0
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1answer
310 views
What is significance of N1 and N2 in Jet engine? [duplicate]
Why N1 Low pressure compressor RPM and N2 High Pressure compressor RPM are monitored in jet engines ?
Why specifically compressor RPM rather than turbine RPM ?
What do N1 and N2 signify in terms of ...
27
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2answers
7k views
What is a rubber engine?
I hear it a lot in engine design , I think that belongs to some phase about we can change the engine parameters according to requirements but I am not sure about it.
3
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1answer
78 views
What is the difference between active tip clearance control system and passive tip clearance control system in turbine?
What are the main differences between turbine active tip clearance control system and passive tip clearance control system?
-1
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1answer
137 views
Turbofan design parameters [closed]
I am writing a model for LM Prepar3D to simulate the flight model of a commercial airliner.
The specification I am following requires some parameters from the engine (CFM56).
...
22
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6answers
8k views
Why then don't aircraft fly even higher, for even greater efficiency? [duplicate]
After reading various superb QA on here I now see that (basically) aircraft are more efficient per passenger-mile, at higher altitudes.
Why don't we go even higher, than current typical airliner ...
6
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3answers
3k views
How can flying high minimize drag and increase fuel efficiency? [duplicate]
As a plane goes higher, the engines have to work harder to compensate for the air density, therefore it will require more fuel in order to provide the same power at lower altitudes.
But I always hear ...
0
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2answers
103 views
Why does a turbine engine compressor ratio affect stagnation pressure?
This might just be a misunderstanding on my part, but in an ideal Brayton cycle, the flow through the compressor and turbine is isentropic, meaning $\Delta s = 0$. However, usually you are given the ...
0
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2answers
232 views
Can a Rutan Quickie be made into a legal Part 103 Ultralight?
I was was thinking about buying a 80s rutan quickie q-1, it has a 18 hp motor. I want to get a ultralight but I like this one because it is fast. Can I get a motor that would be within the ...
0
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1answer
77 views
Does the FBW system of a passenger aircraft use differential thrust for yawing? [duplicate]
Are there situations where the fly-by-wire system of a commercial passenger aircraft will use differential thrust to yaw? Or is that even possible at all (i.e. do the necessary interfaces exist)?
I ...
1
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1answer
183 views
How much thrust could a 400 mm EDF produce?
there's a 195mm EDF from Schübeler that produces 25 kg of thrust at a peak power consumption of 15 kW: https://www.schuebeler-jets.de/de/produkte/hst
Now, my question is: How much thrust could you ...
1
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1answer
287 views
51
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3answers
13k views
Could a Dyson fan scale up to be used as a bladeless aircraft engine?
Dyson has been making bladeless fans for a few years now that accelerate a consistent stream of air without exposed blades.
If this concept were applied to aircraft engines, it could potentially ...
5
votes
1answer
556 views
What are the consequences of attaching an unused extra engine under Boeing 747 wing?
It turns out Boeing 747 can carry an extra engine under its left wing in case there's need to transport an engine somewhere far away. The engine is attached between the body and the left inner engine ...
0
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1answer
251 views
Does an airplane need a key to start? [duplicate]
Does an airplane require a key to unlock the doors and start the aircraft engines?
Is it somewhat like how a car does?
0
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3answers
222 views
Does bypass air produce thrust?
How does bypass air exiting the bypass nozzle produce thrust in a turbofan engine?
I thought that thrust was produced by air reacting with the fans. So if thrust happens when there is an action-...
17
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10answers
8k views
Why are all engines identical in typical commercial airplanes?
I come from the IT world where redundancy is in place to cover several cases, among other:
a statistical failure of a device (so we use more of them expecting that the event is independent)
a rogue ...
0
votes
4answers
355 views
Why do we not see propellers on swept wings or jet engines on straight wings? [closed]
Why are these configurations not observed often?
The only time I see propellers are on straight wings or on the nose, while jet engines are always on swept wings or the tail. Why?
1
vote
1answer
364 views
What is the relationship between EGT, Fuel Flow, N1, N2 and Air Temperature?
I initially wanted some sample data for EGT, Fuel Flow, N1 and N2 to build a prognosis system that predicts engine failure (ECTM).
I searched for some sample data online but got to know that there's ...
3
votes
1answer
137 views
Where can I find sample data required for Engine Condition Monitoring? [closed]
I'm trying to find some sample data required for Engine Condition
Trend Monitoring to analyse and predict when an engine might fail.
I went through a lot of research papers and (kind of) understood ...
0
votes
0answers
44 views
Are throttleable rocket engines the less efficient the lower the power setting?
Are throttleable rocket engines less efficient the lower the power setting? Logically that would lead to lower pressures in combustion chamber and so lower thermodynamic efficiency. Or is it remedied ...
2
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2answers
691 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-...
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1answer
459 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 ...
3
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3answers
342 views
How does the nozzle diameter affect the thrust of a ducted propeller?
I currently do some experiments with ducted propellers in which I try to figure out which effect a nozzle has on the thrust produced.
My theory goes like this: If I reduce the exit diameter of the ...
9
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2answers
4k views
1
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2answers
108 views
What are technical and aerodynamical limitations to blown wings main propulsion?
Why wouldn't some blown flap or blown wing device (suppressing propeller or fan or jet exhaust from aircraft design) produce sufficient thrust needed for takeoff and cruise flight, opposed to "only" ...
0
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2answers
379 views
Are two little engines or one big engine more efficient for an ultralight?
For an ultralight, should two engines weighing 10kg each and making 7hp each OR one engine weighing 20kg and making 14hp be used?
1
vote
1answer
415 views
What happens during Engine Performance Restoration
What is the typical process during an Engine Performance Restoration?
I am trying to find a resource that gives an overview of what happens but I have not been successful.
Any help would be much ...
0
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0answers
46 views
Three-engine jetliners [duplicate]
Why three-engine jetliners were popular in the 1970s?
Why they are no longer in production?
In case of engine failure, did the 3rd engine not reduce the thrust asymmetry? to keep the aircraft in ...
3
votes
3answers
280 views
Is it possible to build a flight-capable aircraft powered by compressed gas?
I pray this isn't a physics SE question.
A star engine can be considered "gas operated". So what if we power a star engine with unleashed, formerly compressed gas instead of... actual gas/aero-...
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1answer
92 views
How does a turbojet power its own compressors? [duplicate]
The title says it all, does the compressor use electricity? if so, how does it generate this electricity? The main power source can't be from the compressor itself as it would lose more power than it ...
0
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0answers
45 views
What's the point of the impact air tubes in the RSA FI system?
As part of the RSA/Bendix fuel injection system, the air metering force controls the fuel poppet, a valve that closes or opens to vary fuel flow. The air metering force is comprised of a diaphragm ...
1
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0answers
68 views
Is there a standard install direction of the abradable shroud honeycomb on a CF6-80c2 engine?
Is there a standard install direction of the honeycomb cells on the Fan Forward case on the CF6-80C2 abradable shroud section?
I have seen engines that the honeycomb cells run point to point front ...
13
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1answer
4k views
Which jet engines have the highest thermal efficiency?
Some automakers (Mercedes-Benz, Toyota) have recently been making news about the improved thermal efficiency of their engines, stating that they reached the 50% mark. I was wondering if it was the ...
1
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1answer
147 views
How are the NEO LEAP-1A engines attached on the A320?
How many bolts hold the NEO LEAP-1A engine to the pylon at the forward mount and at the aft mount?
2
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2answers
181 views
What were the make and model of the engine that failed in flight Southwest 1380?
Regarding the tragedy of Southwest 1380 flight on 2018-04-17 involving an engine failure, what company manufactured that engine, and what engine model/type was it?
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1answer
115 views
In BGA or ATR's what are the major causes of ODOR in Cabin or Smoke in Cabin? [closed]
In BGA or ATR's what are the major causes of ODOR in Cabin or Smoke in Cabin?
There are some of the maintenance activities that are related to removal of Engines or APU.
Removal reason: Smoke in cabin ...
0
votes
1answer
179 views
What forces act on cascade-type thrust reverser blocker doors?
What is the stress or force that loads the cascade-type thrust reverser blocker doors? As we know, blocker doors are closed and block the airflow going through the C duct. The engine is a V2500 with ...
1
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2answers
74 views
What are the main sensor value that cause High pressure compressor fault in turbofan engine?
I have read the paper "Damage Propagation Modeling for Aircraft Engine Run-to-Failure Simulation" (Reference).
I am doing analysis to find which sensors to monitor for the faults injected in the ...
