Use for questions relating to flight at speeds greater than sound and related effects from doing so.
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29 views
Creation of normal shock wave
Can it be said that normal shock wave is a series of intersecting mach lines which unite together and form the shock, or is that just true for an oblique type of shock wave?
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0answers
37 views
What is the importance of Mach number (M) on shock waves?
My primary question is: what is the importance of Mach number (M) on shock waves? Although I believe confirming and/or answering the below will help clarify my misconceptions.
When a wave moves ...
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0answers
10 views
How to determine maximum loads on control surfaces for supersonic flight
I checked control surface sizing and actuator selection having some estimates, but are largely meant for subsonic flight adhering to FAR regulations which dictate the maximum loads and flight ...
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0answers
59 views
Why do so many supersonic aircraft feature delta wings and elevons?
Commercial and military supersonic aircraft constantly favor the delta configuration if they exceed the sound barrier, and also tend to be tailess or twin tail. What is the reason behind such designs? ...
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2answers
207 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 ...
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1answer
81 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 ...
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1answer
98 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
34 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 ...
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97 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 ...
2
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0answers
181 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 ...
3
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1answer
130 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 ...
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2answers
731 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?
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3answers
154 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 ...
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1answer
257 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 ...
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4answers
407 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 ...
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2answers
437 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 ...
12
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1answer
426 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
333 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
138 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 ...
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2answers
148 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
924 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 ...
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2answers
567 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 ...
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1answer
175 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 ...
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1answer
141 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 ...
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1answer
141 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 ...
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0answers
226 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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2answers
105 views
What are the pros and cons of using shielding as opposed to liquid cooling the skin of supersonic aircraft?
What are the pros and cons of using shielding as opposed to liquid cooling the skin of supersonic aircraft? This is in light of the fact that most shielding materials used in aircraft, like ceramics, ...
3
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0answers
263 views
What is the effect of Mach number on efficiency, thrust and specific fuel consumption of a ramjet engine?
My graphs show that overall efficiency and thrust first increase, reach a peak and then fall in the supersonic range (M=1-5) whereas SFC first and then increases rapidly near M 5.
Why does this ...
6
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2answers
2k views
Do USAF fighter jets go supersonic over land?
Does the US Air Force operate supersonic fighter jets over land?
I heard that the FAA banned supersonic flight over America due to the shockwaves creating loud booms and breaking windows on the ...
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3answers
3k views
Are there any planes that have ramjet or scramjet engines?
Are there any planes that have ramjet or scramjet engines? If so, how did they reach the required mach speed for the engines to start functioning?
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5answers
1k views
Why are there no Mach 4+ fighter planes?
Why are there no Mach 4+ fighter aircraft? It seems that such aircraft would have massive advantages when it comes to being able to fire longer range missiles and evade return fire.
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1answer
360 views
Is hypersonic flight possible with a Busemann's Biplane?
The modifications to the Busemann's Biplane design reported in this article have proven that it is possible to design a modified Busemann's Biplane wing design that actually produces lift at ...
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3answers
231 views
What is the maximum speed for regulation of sonic boom noise?
If fuel cost and fuel efficiency were not the issue, what is the maximum speed (air speed and ground speed) that business jets or airliners could travel at without exceeding the maximum noise and ...
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1answer
539 views
If no low-speed compromises were made, what would an ideal Mach-3 wing look like?
Things like the Concorde and Tu-144 and many other supersonic craft need a wing that has good high-speed and good low-speed performance. After all, it needs to be able to take-off and land. Good low-...
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2answers
475 views
Is it possible to hear a sonic boom when the aircraft is exactly at Mach one?
Will an observer on the ground hear a sonic boom if a plane passes overhead at exactly the speed of sound? That is, the plane does not cross the sound barrier. The plane just hits Mach one - and ...
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0answers
34 views
How could aerodynamicists reduce the intensity of the sonic boom? [duplicate]
My understanding of the sonic boom is that it is caused when shockwaves being emitted from an object travelling at Mach 1 or above compress and superimpose on each other because they cannot move out ...
3
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2answers
300 views
Can a lifting body work at supersonic speeds?
Can lifting bodies be made for supersonic flight, say up to Mach 3? What would they look like? How would they differ from lifting bodies for normal subsonic flight?
3
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2answers
227 views
Would winglets add fuel efficiency on a Concorde? [duplicate]
Would adding winglets to a Concorde have a had a positive impact on its performance and fuel efficiency in retrospect, considering the technology was not widespread or developed at the time these ...
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4answers
714 views
Can a supersonic aircraft have winglets?
In order to have laminar flow over the wings which helps in friction drag reduction, a number of airfoil designs have been proposed from the past to the latest 737 winglets.
But if we design a ...
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2answers
534 views
Does the sound barrier apply to a silent aircraft? [duplicate]
For my summer duty, I was looking at the sound barrier effects with a glimmer of hope to understand them:
"A supersonic aircraft is one that can travel faster that the speed of sound. As the plane ...
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2answers
610 views
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 ...
10
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0answers
905 views
How loud was the Concorde's sonic boom at the ground level? [duplicate]
Before the Concorde was sent into retirement, their supersonic flight paths were restricted to the ocean because of concerns about sonic boom on the ground.
But just how loud was this boom? Was it ...
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1answer
549 views
Why does the aspect ratio of a wing become less important at supersonic speeds?
My understanding is that an increase in the aspect ratio (AR) of a supersonic wing won't increase the efficiency like it would for a subsonic wing.
If the subsonic induced drag is:
$C_{D_i} = (C_L^2)...
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1answer
270 views
How does the pitching moment change as the speed of A/C approaches critical Mach number?
In an aircraft performance course, I saw that pitching moment goes backwards as the speed of A/C approaches critical Mach number. In fact, that results in nose down pitching moment. But, according to ...
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1answer
246 views
private jet based of an sr 71 [closed]
could a private jet be based of an SR 71 blackbird. By this I mean similar styling and shape. Would this be a good basis to make a private jet super sonic (disregarding sonic boom). What would the ...
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2answers
384 views
Could a modified J58 jet engine be used commercially?
Could this mean for more fuel efficient supersonic commercial cruising?
If so in what ways would it need to be modified and how possible is this?
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1answer
249 views
What would happen if the wing of a supersonic plane goes into the shock wave from the nose?
What happens if the wing of a supersonic plane goes into the shock wave from the nose?
A plane have this shock wave at the nose going back at an angle, but it also have shock waves going back (in the ...
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1answer
201 views
At which speed is a plane traveling at hypersonic? [duplicate]
What is the measurement used when a plane is said to travel at hypersonic? How does the air act at the nose of the plane? Would the nose and wing have to be razor sharp to cut the air? because the ...
10
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2answers
1k views
Can a supersonic plane use a subsonic wing if the nosecone shock produces subsonic airflow around the wing?
A supersonic plane will produce shock waves off the nose cone, as seen below:
These oblique shocks reduce the speed of the air that the wing experiences. If the plane is at a low enough Mach number, ...
2
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2answers
646 views
Could a tilt quadcopter use turbofan engines?
I was wondering whether having a quad tiltrotor would allow for the use of turbofan engine rather than turbo prop. I read on another question that the V-22 uses turbo prop as it is easier to balance, ...
