Questions tagged [supersonic]

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

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12
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4answers
3k views

What is a ramjet?

What is a ramjet? Was it used on the SR-71 Blackbird?
14
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2answers
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Why is the coefficient of drag for straight wings at supersonic speeds lower than for swept wings?

Why is the coefficient of drag of a straight wing lower than the coefficient of drag of a swept back wing at higher supersonic speeds (above, say, Mach 2)?
15
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1answer
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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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5answers
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Why are there no commercial supersonic flights at present?

I'd think that on certain heavily trafficked routes, especially ones with lots of business travelers, there would be a market for high-speed (supersonic) flights? Why are there currently no ...
17
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2answers
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What control issues did the X-1 have to overcome to achieve supersonic flight?

In Chuck Yeager's autobiography, he went into a little bit of detail as to why the X-1 was able to break the sound barrier safely where as the P-51D he flew during WWII could not have safely broken ...
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2answers
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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 ...
10
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2answers
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What are the advantages and disadvantages of a delta wing compared to a swept wing?

What advantage does a delta wing have over a swept wing with high AR for supersonic flight? And what disadvantage does a delta wing have over a swept wing with high AR for transonic flight? The ...
20
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3answers
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What is a high speed stall?

I'm told that planes can actually stall when the airflow over the wing goes past Mach 1? Why does this happen and how do you design an aircraft to avoid it?
16
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4answers
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Why are swept wings better for breaking the sound barrier?

I'm told that swept wings perform better when an aircraft is trying to break the sound barrier. I was wondering why that would be?
9
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2answers
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What causes the reduction in speed across the shockwave?

Wherever I read about shock waves, it is mentioned that there is a reduction in speed across the shock wave. Can someone please explain what happens at the molecular level, i.e. the physics of the ...
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3answers
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Can propeller driven aircraft sustain speeds at or above Mach 1?

Has any propeller driven aircraft ever achieved and sustained supersonic speed? If not, why can't propeller airplanes achieve that speed?
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3answers
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Did the XF-84H Thunderscreech really cause “900 sonic booms per minute”?

The Republic XF-84H, known as the "Thunderscreech" was an experimental version of the F-84F Thunderstreak. It was intended to be a supersonic turboprop fighter. Even at idle, the prop tips rotated at ...
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2answers
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What is the simplest way to explain a sonic boom that is still technically correct?

I'm looking for an explanation that preserves technical accuracy while remaining brief. Bonus points for including the double boom. Try to avoid discussing laminar flow and such.
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4answers
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Is there a boomless sonic technology in any state at this time?

I've heard rumors about airplanes being on the horizon with "boomless sonic" technology, or the ability to fly supersonic without creating that hazardous shockwave. This would be very valuable for ...
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2answers
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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 ...
21
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2answers
11k views

Can a sonic boom produced at 60,000' be heard on the ground?

The Concorde normally cruised at an altitude of 55-60,000 feet, but wasn't allowed to fly over populated areas due to the noise it produces. Can the sonic boom of an aircraft at 60,000 feet be heard ...
4
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1answer
2k views

Why most of the supersonic or fighter aircraft use all-moving control surfaces?

What are the advantages of using all-moving control surfaces? can someone give explanations based on aerodynamics?
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2answers
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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, ...
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2answers
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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 ...
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3answers
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Why did Air France retire Concorde? [closed]

It was developed by British Airways and Air France in the 1970s as the first supersonic passenger/civilian airplane.
5
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1answer
250 views

When and where are anti-ice required for supersonic flight?

Many aircraft have heating devices to prevent dangerous icing. Supersonic aircraft rapidly compress the air, leading to elevated temperatures. Concorde and Tu-144 used fuel as a heat sink. How fast ...
4
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4answers
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Did Concorde really fly above 55k feet as mentioned in this report?

Here is a report of the last journey of Concorde from JFK-LHR, which mentions "The highest altitude we reached was 58000 feet." Is this height aerodynamically feasible to reach?
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2answers
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How is supercruise achieved?

Wikipedia article tells that supercruise is a condition when an aircraft can achieve velocities above Mach one without using the highly inefficient afterburners. But still, there are not a lot of ...
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How can the landing gear fit in the small room in the engine bay on the Tupolev Tu-144?

I recently went to the museum in Sinsheim, Germany, where a Tupolev Tu-144 is on display. I noticed that the landing gear of this plane is actually way wider than the space it has available when ...
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1answer
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How are condensation cones created by supersonic airplanes?

There are many awesome pictures of this phenomenon such as this one: What is the physical explanation of how this occurs? Does it occur only when the airplane crosses the sound barrier or does it ...
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2answers
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Can turboprop blades break the sound barrier?

This question doesn't relate to the actual speed of the aircraft, but of the blades themselves. I have heard helicopters had problems of this happening if the rotors spin too fast it can break the ...
4
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1answer
254 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 ...
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1answer
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Could a test crew replicate the 1961 DC-8 supersonic dive in a more modern airliner?

The first airliner to ever break the sound barrier was the DC-8, doing so in a semi-famous dive from 52,000' to 35,000' over the Edwards test range on August 21, 1961. Could this supersonic dive be ...
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1answer
799 views

Are there any serious plans for a new supersonic civilian aircraft? [closed]

Since the retirement of the Concorde and the Tupolev Tu-144, there aren't any civilian airplanes (passengers carrier or business jet) flying supersonic. I heard that Dassault and SAAB had rather ...
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1answer
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Would a perfectly silent supersonic aircraft create a sonic boom?

Assume that you have an aircraft that is so amazingly stealthy that it is perfectly quiet: no engine noise at all, nothing. And, it's going supersonic. (Maybe in a steep dive with the motor shut off....
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2answers
523 views

Does lateral stability decrease during transonic flight? If so, why?

I haven't got much more to explain other than the title of the question itself. This question was written down in my notes that I took while studying Principles of Flight for my EASA commercial ...
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4answers
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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 ...
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6answers
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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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0answers
294 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 ...
3
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1answer
933 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 ...
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1answer
304 views

Does jet engine exhaust velocity relative to itself remain constant despite speed changes?

Maybe this is a stupid question. I seem to have been told, the velocity of the exhaust leaving an airbreathing jet engine relative to the engine, is constant despite changes in airspeed. However, to ...
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3answers
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Why does centre of pressure (drag?) move forward when transitioning from transonic to supersonic?

I am studying aerospace engineering at college and I am wondering why the centre of pressure moves forward when the aircraft changes from transonic flight to supersonic flight? Also, is centre of ...
0
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1answer
139 views

About ramjet efficiency in supersonic speed. Is there an optimal speed?

I know there is an optimal speed for ramjet. This are the results of my research. The reason the efficiency increases with supersonic speed to an optimal value then decreases is related to the ...
18
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1answer
2k views

Do bigger aircraft make a bigger sonic boom?

I was watching an episode of MythBusters where they were trying to break glass windows and cups using a sonic boom generated by a F/A-18 Hornet, flown by the Blue Angels. In summary, they were ...
13
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2answers
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Could Concorde have used swing wings?

Would it have been possible to equip the Concorde with swing-wings to help with lift at lower speeds? The delta wings on the aircraft worked well at high speeds, but it took a long time for it to ...
7
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2answers
869 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 drops and then increases rapidly near M 5. Why does this ...
3
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1answer
625 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 ...
16
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1answer
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At what altitude did Concorde go supersonic?

At what point during flight would Concorde go supersonic? Would it climb to cruising altitude first? Does altitude affect the transsonic difficulties (buffet, need for extra thrust, etc.)?
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8answers
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Could an airliner exceed Mach 1 in a zero-G power dive and safely recover?

(I looked for duplicates. I really did.) Being as it is that "safety" and this are mutually exclusive: I am stupid. I take a cruising A320, apply TOGA power, and push zero Gs until I exceed ...
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2answers
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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 ...
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1answer
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Does skin friction drag decrease with velocity?

The wings of subsonic planes have usually a very low surface area and aspect ratio as big as possible. However, in supersonic aircraft, wings with more wetted area (e.g delta wings) are used. Is this ...
4
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4answers
762 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 ...
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5answers
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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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3answers
456 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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2answers
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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?