Questions tagged [inlet]
Also known as intake, is an opening that feeds air to an engine, air conditioning system, oil cooler, etc.
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What is this F-18 Hornet "air intake" for?
I think I read once that they served to cool the on-board computer systems, but I'm not sure.
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Why are turboprop intakes placed below the propeller?
On many turboprop aircraft, such as the A400M and the ATR 72, it seems that the air intake tends to be placed below the propeller (images: Wikipedia):
source
source
Given that mounting the intake ...
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Why are turbofan inlets leaned/angled forward?
(Image Source: Wikipedia)
Seeing that everything is radially symmetric (apart from the nacelle mount, naturally), I wonder why the inlet (the front part of the nacelle) is usually skewed?
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What is the working principle of gravel kits?
In this answer gravel kits are mentioned. I then looked at the wikipedia page and I noticed that they are quite different from what I was expecting:
I was expecting some kind of "shield", plate or ...
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Why is the S-duct intake on the Tu-154 uniquely oblong?
Is there an advantage to the oval/elliptical shape of the Tu-154's S-duct intake? It appears to be taller and an overall different shape than the side-mounted cowlings.
This doesn't appear to be a ...
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Why are the intakes of some fighters not attached to the fuselage?
Look at the photo below. As you can see the intake isn't attached to the fuselage. Why? Other examples include the F-16, F-22, and F/A-18 Hornet.
(F/A-18E Super Hornet Walk Around)
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If the intake of a running jet engine is blocked for some short duration what would be the sequence of events following it?
If the intake of a running jet engine is blocked for some short duration what would be the sequence of events following it? Will it cause any damage to the engine parts?
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What are the merits of an inlet cone/spike/centerbody vs. a 2D inlet?
And which is better for a scramjet?
Is a 2D inlet basically a "2D cone"? Similar to how an aerospike engine is made "2D" in the linear aerospike?
What's inside the cone/spike? Or is it just hollow?
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Why do the 737-100's JT8Ds, and no others, have suck-in doors?
Of the various use cases of the Pratt & Whitney JT8D (the most-produced low-bypass turbofan in history, and the second-most-produced turbofan of any description1), those installed on the 737-100 ...
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What are those half-vanes in the engine inlet of a 707-328?
I just saw this:
Source
They look like IGVs but I'm not sure. What could those be? Do you know the engine?
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What are these small engine inlets on the Super Hornet?
Does anyone know what these two small variable inlets on top of the engines are used for on the Super Hornet?
Source: navy.mil; cropped
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What is this tube in a jet engine's air intake?
I have long been wondering what is the official name of this little air intake tube located in front of the fan blades and its intended functions. I did search it on google but it was in vain. I guess ...
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What is the difference between side-by-side vs under-cockpit engine intakes?
What is the main difference between these two engine configurations?
What are the differences between planes that have the intakes below the cockpit as compared to those who have them on the sides?
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How can an F-22 Raptor reach supersonic speeds without having supersonic inlets?
The F-22 Raptor and some other jets do not have inlet spikes, yet they are able to achieve supersonic speeds. How is that possible?
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What is the function of the holes in splitter plates?
Do the holes in splitter plates reduce the boundary layer, or do they serve a different function such as acoustic/vibration damping?
Many splitter plates have a series of holes drilled into the ...
user14897
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Is the nose cone of the MiG-21 adjustable in-flight?
In some of the photos I saw of the MiG-21, the nose cone was extended and in others it was shortened. So, is the nose cone of the MiG-21 adjustable in-flight to allow for increased/decreased air flow?
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How does a long inlet affect a jet engine's performance?
How, for example, would the long inlet of the tail-engine on an MD-11 or an L-1011 affect its thrust production/performance, if at all?
(Source)
I am not well versed in fluid dynamics, so any ...
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What are these four tubes for in the intake for an Extra 300?
The fuel-injected engine has six cylinders, so it's not a "per-cylinder" thing nor is it related to a carburetor.
P.S. That screen is the entirety of the air filter. Apparently it's meant ...
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What is the purpose of the vertical splitter and the NACA duct at the MQ-9 Reaper engine scoop?
The engine scoop/intake on the MQ-9 features a vertical splitter at the inlet face, as well as another smaller NACA duct on the top cowl surface just aft of the inlet lip.
I am guessing the former ...
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Why is the inlet cone on some subsonic engines conical (sharp)?
An inlet cone, as far as I know, is a component on an engine to guide the intake air smoothly into the compressor stage of a jet turbofan engine, it performs as a fairing(aerodynamic covering)of the ...
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Why does the MiG 21 use anti surge shutters?
Does the MiG-21 use anti surge shutters at high speed? What is the adverse effect on the airflow at such high speeds (despite using a conical spike ahead) which warrants the use of antisurge shutters?
...
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What type of supersonic intake does the Dassault Rafale fighter jet have?
What type of supersonic intake does the Dassault Rafale use? Is it a Pitot Intake? It cannot be a Ramp Intake, nor can it be a Spike Intake / Cone Intake, and it does not seem as a Diverterless ...
user12485
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Which supersonic airplanes use Pitot Air intakes?
Which supersonic (fighter) airplanes use the simple Pitot Air Intakes / Normal Shock Inlets?
Two examples already seen here on Aviation.SE (one and two) are
Dassasult Rafale ($Ma \leq 1.8$)
Image ...
user12485
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Why do the inlet cones on an SR-71 retract at higher speeds while the one on a MiG-21 extends at higher speeds?
As shown by this illustration in the SR-71 flight manual, its inlet cones (spikes) retract as its speed increases:
(source)
Meanwhile, the Wikipedia page for the MiG-21 describes the opposite ...
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How does inlet spillage drag produce a lip suction effect?
From this page:
Spillage drag, as the name implies, occurs when an inlet "spills" air around the outside instead of conducting the air to the compressor face. The amount of air that goes through ...
user14897
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How is the jet engine inlet danger area affected when airborne?
Boeing published engine hazard areas as shown below:
I am curious as to how the danger area is affected when the aircraft is in flight as the jet engine is still vulnerable to foreign object damage.
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Why do the intake of some helicopters have a bump body?
Not all but the intake of many helicopters have a bump body. Why? e.g.
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Why should the dust protection on the Mi-17 helicopter not be used above 3000m?
The Russian Mil Mi-17 helicopters have a dust protection device fitted at engine intake (see the rounded part in front of the intake):
Its checklist gives an altitude limitation from sea level to ...
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What is the temperature of intake air at several speed of sound intervals from 1x to 10x?
I watched a YouTube movie about Reaction Engines development of the Sabre engine which main feature is cooling intake air. However, I cannot find an overview of the temperature of intake air at ...
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How come diverterless supersonic inlets haven't been discovered much earlier?
DSI's seem like such an absolutely elegant solution to a problem that has, so far, been solved in a truly overly complicated way.
So, if I'm not missing out on some important small speck of knowledge ...
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Why does a subsonic nacelle inlet have a throat before the diverging section?
Aircraft propulsion 2nd edition by SAEED FAROKHI" p.340
Aircraft propulsion 2nd edition by SAEED FAROKHI" p.123
As we can see from the image, the nacelle slightly converges towards a throat, before ...
user38325
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What is the purpose of a movable inlet on a jet engine?
I was reading that aircraft like the F-15 and SR-71 have movable inlets. What's the purpose of this?
I was also reading aircraft like the F-22 doesn't have a movable inlet. Why?
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How does a subsonic jet engine intake design ensure correct air intake?
I think I understand that inlets are there to slow down the airflow and increase the pressure to stop the compressors stalling?. If this is the case, I don't understand how the nacelle or intake ...
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Why are turbofan inlets circular- or oval-shaped instead of square-shaped?
Source: materialsengineeringconsultant.com and initious.blogspot.com.
Most of the engines are circular except for some that are oval. The oval shape provides a better ground clearance.
Why aren't ...
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What is the function of variable inlet guide vanes in terms of pressure change?
Nowadays in the turbofan Variable Inlet Guide Vanes are more and more used. My question is: which is their function in terms of pressure change?
The question is very specific: I know that they allow ...
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What is the tapered cone on the B747 CF6 engine inlet cowling?
B747 and B767s are supposed to be using exact same GE CF6 engine, and as such their components are interchangeable including inlet cowl as they show to be effective in the IPC.
However some of the 747 ...
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Why is there an intake in front of the landing gear on this C-160?
I went to a aircraft museum and saw this C-160, it has intake in front of the landing gear which is now blocked with the orange thing as you can see below in the picture below. Why is there an intake ...
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Do nose cones work well at high angles of attack?
On a lot of fighter jets, I see a heavily slanted intake, such as the F-15.
I always thought this is to help ingest air at high angles of attack. However, what about something like the MiG-21?
There'...
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XB-70 inlet duct working method
Jenkins and Landis write in their 2004 book about the XB-70, regarding its inlet duct:
"Three movable panels, positioned by two hydraulic actuators, opened or closed the throat area to meet ...
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Do ramjets use variable geometry supersonic inlets?
Ramjets are very often portrayed as super simple, I've read on few occasions that the only moving parts in a ramjet are the fuel pumps. However, turbojets operating at similiar speeds (mach 2 - mach 3)...
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What type of flow is preferable for jet engines?
I would like to know how laminar/turbulent flow affects engine performance. Any additional thoughts on the topic, even if not strictly related to the main question, are welcomed.
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How is the flow of air through a NACA submerged inlet determined?
This question pertains to the design and/or selection of NACA submerged inlets. I am trying to understand what kind of airflow would enter a NACA submerged inlet/scoop and am looking for a good ...
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How is the F-22's nacelle/engine bay ventilated?
How is the aircraft skin around the engine bay in the F-22 cooled?
As in the F-35, there are scoops below the wings, which provide ram air around the engine bay, but you don't see any scoop around in ...
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What different intake designs are there, and what are their pros and cons?
I noticed that over the years (on fighter jets specifically) there have been many different methods of directing air into the engines. Primarily, the nose-intake, side intake, and underbody intakes ...
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What drives the shape of an engine's intake on a fighter jet?
Rectangular intakes have more corners which might increase subsonic pressure losses and would weigh larger than a pitot (Semi-circular) type intake. Are the designer drivers solely based on supersonic ...
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What is a ram recovery point?
As aircraft speed increases, thrust tends to decrease somewhat; as the aircraft speed reaches a certain point, ram recovery compensates for the losses caused by the increases in speed. The inlet must ...
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Why is an air intake located on the root of the tail on some aircraft?
There is a small air intake on the root of the tail of some aircraft, especially those with engines near the end of the aircraft. What is it and why is it located there?
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Does intake mass-flow rate vary linear proportional with turbine fan speed?
Is jet turbine intake mass-flow rate linear proportional with its fan speed (N1)?
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Are there aircraft with multiple inlets for a turbojet engine?
Are there aerial vehicles which have multiple inlets with air ducts (shaped in S-forn) , which all lead the air to one single turbojet engine?
I have not enough space to put just one inlet area on my ...
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How hot is supersonic intake air?
How hot is the air at the compressor inlet at supersonic speed? For instance the Concorde at mach 2.2 or other jet engines at even higher speeds.
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