Aviation

Questions tagged [supersonic]

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Use for questions relating to flight at speeds greater than sound and related effects from doing so.

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7
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1answer
55 views

Since shock waves have non-negligible viscosity, why do the normal shock relations ignore friction/viscosity?

The normal shock relations (seen below) are derived by using steady, 1D, neglect potential, no shaft work, adiabatic and zero viscosity assumption. However, since shock waves are "thin regions of high ...
1
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0answers
82 views

Supersonic propellers for supersonic aircraft? [duplicate]

A propeller is a spinning wing. Supersonic wings work. So, provided that the blades are made wide-chord and thin like supersonic wings are, with a supersonic airfoil, can they not power efficiently a ...
5
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3answers
279 views

Do afterburners use excessive amounts of fuel?

The purpose of an afterburner is to provide additional thrust, and it is obvious that more fuel is needed for that. But that is to be expected independent of an afterburner. That more thrust needs ...
18
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6answers
6k views

Is an afterburner louder than the same jet engine without it?

I would speculate that an afterburner increases the noise because it is nearer to the exhaust. But it certainly causes so many changes in the exhaust flow that it could be less loud as well. It may ...
10
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1answer
5k views

Will you be able to hear a supersonic aircraft flying away from you?

I'm wondering if you could be able to hear the sound emitted by an aircraft say traveling at Mach 2 away from you. I wondered if it might shift the emitted frequencies beyond the audible range. Would ...
-2
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1answer
150 views

Is the “Boom” project vaporware or really going to happen? [closed]

Is this https://boomsupersonic.com viable or more vaporware? Any solid information?
3
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0answers
100 views

What will happen to wing Vortices on supersonic aircraft?

Having looked at the new Aerion AS2 design I wondered whether anyone could tell me what happens to wingtip vortices at a cruise of Mach 1.4 with the strange wing shape of the AS2 design? I know that ...
1
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1answer
229 views

Why doesn't Concorde stall when passing Mach 1, where a normal airliner does?

As Jay Carr asked: What is a high speed stall?, Jan Hudec explained: A difference from normal stall is that after supersonic flow separation the lift remains proportional to angle of attack and so ...
10
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2answers
2k views

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?
20
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4answers
5k views

Was the Boeing 2707 design flawed?

The mach 2.7 capable Boeing 2707 has an interesting design. I'm curious if there has been any studies done that concluded that this aircraft would simply not have worked, given the way it was ...
52
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3answers
12k views

Can you feel passing through the sound barrier in an F-16?

Is it possible for the pilot to feel passing through the sound barrier in an F-16? What about other modern aircraft, will you feel anything? Do you need to go back to really dated designs before you ...
4
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1answer
115 views

How do a narrow airframe and canards keep supersonic shock waves from coalescing?

In a follow up to my previous question: How does the X-59 acheive quiet supersonic flight? Canards and a long narrow airframe were cited as design choices to prevent shock waves from coalescing. How ...
2
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1answer
207 views

How does the X-59 acheive quiet supersonic flight?

By what mechanism or combination of mechanisms does the X-59 reduce the noise produced by a sonic boom? What are the design choices that lead to quiet supersonic flight? I really want to understand ...
15
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2answers
771 views

Acceleration of a supersonic aircraft after breaking the sound barrier

People on the physics stackexchange recommended I ask here, so I am pasting my question regarding supersonic aircraft. I stumbled upon an interesting plot; in particular, the dependence of wave drag ...
3
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1answer
327 views

Could the Olympus 593 have been windmill-restarted during supersonic flight?

The Rolls-Royce/SNECMA Olympus 593 (which powered the Concorde) used a complex intake-ramp system to improve the engine's efficiency and prevent an engine shutdown or failure during supersonic flight ...
4
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0answers
132 views

Aerospike nose cones for supersonic jets?

Not to be confused with aerospike nozzles. This is about the big pin-like rod in front of ICBM nose cones. This answer (from Space) about aerospike nose cones notes that one of the potential ...
11
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2answers
894 views

How is the camera positioned for these plane-to-plane Schlieren images of shock waves?

These two popular press articles discuss the use of schlieren photography to image shock waves of jets during flight using a special schlieren camera on a third plane. Gizmodo: NASA Captures First-...
2
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1answer
51 views

Are there any special considerations involved in designing manual flight controls for supersonic/hypersonic aircraft?

What things, if any, might need to be taken into account in the design of manual flight controls for supersonic or hypersonic aircraft that wouldn’t need to be taken into account with manual controls ...
4
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1answer
129 views

How does a weak shock-wave boundary-layer interaction create wave drag (other than through direct shock losses)?

I'm trying to understand the physical cause of wave drag, beyond the simple statement "the presence of shockwaves increases the drag". As far as I understand, in the case of a weak BLSWI (so without ...
23
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2answers
3k views

Could anyone (non-military) in the present day “exceed mach 1 over a regulated area”?

There is a question What would happen if I exceeded mach 1 over a regulated area? I wonder, could anyone in civil aviation (not military) actually carry out this violation? I know there are privately ...
4
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4answers
666 views

What would happen if I exceeded mach 1 over a regulated area?

What would happen if I exceeded mach 1 over a regulated area? Are there any penalties in place for this violation? Would ATC actually know I’m flying supersonic or would they have to go out of ...
-5
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1answer
348 views

Can electroaerodynamic propulsion be used to circumvent sonic booms?

MIT researchers have created and flown the first plane that doesn’t require any moving parts. “Although it is still a long way off from commercial gas turbine propulsion … electroaerodynamic ...
1
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1answer
103 views

Is high speed buffet possible at supersonic speed?

Since high speed buffet is caused by boundary layer separation due to shock wave and at supersonic flight there is no shock wave directly onto the airfoil (it is attached to the trailing edge), is ...
7
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1answer
175 views

Why does strong shock wave-boundary-layer interaction produce a bubble reattachment?

The picture represents a lambda type shock wave, separating the boundary layer at its foot. Separation causes a recirculation bubble to appear. I understand why separation has happened, but what is ...
3
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1answer
195 views

What are some of the fastest UAVs? How do the pilots ensure that their controls are being transmitted to actions?

I would clarify that the drones I refer to are UAVs that were piloted using a control station. I know many military projects include such capabilities but I want to know how pilots work on such ...
0
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1answer
134 views

What kind of flight termination measures are taken for supersonic aircraft?

Having recently read an article that hyper-sonic airplanes carry enough energy that just flying into some target makes them as powerful as some missiles and I wonder if the supersonic planes have ...
2
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1answer
243 views

What kind of damage would low-level supersonic flight inflict?

I was watching a video about "The Big Stick" aka Project Pluto, a nuclear powered SLAM. In the video (I couldn't find the exact video) it said that after deploying its weapon payload a SLAM could fly ...
1
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3answers
329 views

Why do suborbital planes feature H-tail and/or large wingtips?

Spaceplanes that are suborbital are mostly supersonic and feature H-tail or rather large wingtips. This looks to be similar to a H-tail configuration but I'm unsure abut how it works, which is why I ...
1
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1answer
1k views

What is primary cause of shock induced separation (shock stall)?

In the video link above describing Prandtl Meyer Waves, lecturer stated (at 22:40) a very important fact on which he based his first half of the lecture. "Mach wave (mach lines) deflect the flow ...
2
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1answer
372 views

How can one approximately guesstimate wave drag?

Wave drag is an especially high drag that affects supersonic vehicles above mach 1, but I've found it hard to find source materials to estimate wave drag. I'm looking at the transonic region till Mach ...
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0answers
42 views

What happens to the neutral point of a fighter jet during supersonic flight? [duplicate]

I understand that for a fighter aircraft, it would have to be inherently unstable. To do this I believe that the neutral point needs to be aft of the cg. I was told that during supersonic flight this ...
0
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0answers
118 views

What would need to change for supersonic airliners to be the norm? [duplicate]

I know that supersonic airliners have never been widespread, by reason of cost, engine technology, aerodynamics. Yet can these difficulties be overcome within the next 20 years? I know of Concorde's ...
6
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1answer
422 views

How are the Tupolev Tu-95's blades shaped?

The Tupolev Tu-95 "Bear" seems like an awfully cool piece of innovation with its unusual contra-rotating supersonic-tipped props. From what I've been reading it sounds like it's been the only mass ...
4
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1answer
234 views

What might the business model be for a hypersonic jet? [closed]

According to this video, NASA and Boeing are doing research into a new generation of hypersonic passenger planes that can travel at Mach 5. The designs look really cool and I would love to see them in ...
8
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2answers
579 views

How did this F/A-18's execute a “low-boom maneuver”?

The Engadget article NASA will publicly test quiet supersonic technology in November says: The administration plans to conduct a series of public tests around the coastal city of Galveston in ...
16
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2answers
995 views

What are the procedures for flying supersonic over international waters?

Supposing I owned a supersonic aircraft eg a MiG-21 and wanted to fly the jet out into international waters for a supersonic speed run. Are there any particular ATC procedures for doing so?
2
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3answers
201 views

What mechanism or design aspect prevents jet blast from escaping the front of a Ramjet or scram jet?

Enormous air pressures result in the thrust of a Scram jet or ramjet engine, more so the pressure required to drive the aircraft forward at supersonic and hypersonic speeds. Given that these engines ...
5
votes
1answer
675 views

Could Mach 1.4 be a better design point for SST?

There's been a number of recent proposals for design work on low-supersonic bizjets that would cruise at Mach 1.1-1.6, the common theme being avoiding a sonic boom. I'm wondering if this range of ...
3
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4answers
580 views

What is this transport aircraft, and why does it sometimes cary an air data boom when the Soviet Buran Space Shuttle is on top of it?

This comment in chat points to a "google search of the day" which was for Buran the Soviet version of the Space Shuttle. Looking there I saw images of a large transport aircraft with the Buran shuttle ...
3
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2answers
1k views

Why did the FAA ban all supersonic flights over the United States, rather than only supersonic flight in densely-populated areas?

A major part of why the Concorde was far less of a hit than predicted, and of why the many 1980s and 1990s supersonic transport projects never got off the drawing board, was that the FAA had banned ...
13
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1answer
669 views

Did Concorde's sonic booms affect other air traffic?

Given that Concorde's sonic boom reached the ground, it also must have reached other nearby air traffic. How was this dealt with? I imagine passengers would not welcome hearing a loud boom during ...
3
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1answer
755 views

Why are there no supersonic propellor driven aircraft? [duplicate]

Pretty self explained in the title. Yes, I realize there is no widespread demand for them; this is not what I'm looking for in an answer. I'm looking for an answer that covers more why they can't be ...
2
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1answer
291 views

At what Mach Number do variable cycle engines (VCEs) start showing benefits over turbofans?

Currently, most supersonic engines engines are low bypass turbofans. However turbofans start becoming infeasible as the mach number increases. Variable Cycle Engines, still have noise and weight ...
-2
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2answers
177 views

Would pressurised air holes on supersonic aircraft mitigate the heat problem?

Would air holes or tubes of 50mm diameter blowing pressurised air outside the surface of a hypersonic or supersonic aircraft mitigate the problem of heat? They would be placed such that when they blow,...
3
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1answer
1k views

Is there a limit to the possible altitude for electric jets?

So I was thinking about Elon Musk's supersonic electric jet idea. Assuming we have sufficiently energy-dense batteries, where would the limits be in terms of speed and altitude. His logic seems to ...
2
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2answers
876 views

How will the Boom SST not require an afterburner?

The company Boom is developing a supersonic airliner (SST). In one of their blog-entries1 they state they would not need to use after-burners because they use modern turbo-fan engines. Does this ...
4
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1answer
434 views

what is the highest and lowest air pressure induced by an aircraft at supersonic speeds?

When an aircraft is supersonic, is the greatest pressure at the wing leading edge, below the wing surface or in front of the shock wave, or another location all together. Also is the lowest pressure ...
5
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1answer
196 views

Could the Busemann's biplane concept be used in a turbofan engine?

Would incorporating the Busemann's biplane concept in the turbofan engine fan blades and engine casing make it more efficient, if fan tip speeds were allowed to move above the speed of sound by ...
6
votes
1answer
160 views

Is there any common research model for supersonic transport?

Is there any common research platform, like the Common Research Model of NASA for supersonic transport flight? I assume that in aerospace industry, every company has his own research platforms ...
3
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0answers
281 views

Could supersonic transport make a comeback? [duplicate]

When the Concorde was retired from service, reasons given included: It was expensive to operate; it burned a lot of fuel and had high maintenance costs, resulting in high ticket prices Could only ...

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