Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [engine]

For general questions related to aircraft engines; use [tag:jet-engine] or [tag:piston-engine] if possible.

8
votes
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
vote
2answers
130 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 ...
0
votes
0answers
59 views

Would a Turbofan engine benefit from another fan? [closed]

From my understanding most of the thrust from a turbofan comes from the fan that is driven by the energy generated from the engine through the compression, combustion, and turbine that drives the ...
0
votes
5answers
198 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
vote
2answers
116 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
votes
1answer
160 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
votes
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
votes
1answer
170 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
votes
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
votes
1answer
70 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
votes
1answer
124 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
votes
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
votes
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
votes
2answers
84 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
votes
2answers
216 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
votes
1answer
72 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
vote
1answer
170 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
vote
1answer
256 views

Gas Turbine Engine Starting Sequence [closed]

How to explain the figure above?
48
votes
2answers
12k 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
544 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
votes
1answer
228 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
votes
3answers
203 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
votes
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
323 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
313 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
124 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
votes
2answers
570 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-...
-1
votes
1answer
376 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
votes
3answers
294 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
votes
2answers
4k views

What airplane is this? and why the strange inlets?

Why does it have such strange intakes?
1
vote
2answers
105 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
votes
2answers
326 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
375 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
votes
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
277 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-...
-2
votes
1answer
90 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
votes
0answers
40 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
vote
0answers
66 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
votes
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
vote
1answer
139 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
votes
2answers
179 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?
-1
votes
1answer
108 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
162 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
vote
2answers
69 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 ...
2
votes
2answers
204 views

Which engine manual must a pilot legally use?

Many aircraft have engine/prop performance information provided by the manufacture such as Bonanza, Cessna, Mooney, etc AND the engine manufacture. The performance or recommended settings may vary ...
2
votes
1answer
684 views

Are there any differences between turbofan and turbojet engines besides bypass air?

I think I understand both engine types, but I am just wondering am I right in saying that the only difference between the two types of engines is the bypass air (i.e. a turbofan is just a turbojet ...
1
vote
0answers
134 views

How are turbine blades overhauled?

How are turbine blades overhauled? What techniques are commonly used and how does it affect the integrity of the blade?
7
votes
2answers
2k views

How are engines numbered?

On a commercial aircraft, the number of engine is usually 2, 4 or 6. When the technician or LAE was given task to inspect an aircraft engine no 2 on a 4 engine aircraft. Which engine would they go to? ...
5
votes
1answer
348 views

Is feather edge bad?

Currently learning about aircraft piston engine. Feather edge can be found at the engine valves as according to the picture. Can someone explain briefly about what is feather edge? Why it is bad? ...