Sonic Boom & Condensation Trails: Explained

In summary: The sonic boom is the loud noise created when a high pressure wave followed by a low pressure wave of sound waves collide. The high pressure wave pushes the air molecules ahead of it, while the low pressure wave pulls the air molecules back. The high pressure wave creates a sonic boom, while the low pressure wave creates the condensed water coner.
  • #1
ponjavic
225
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Could someone try to explain to me the reason for the sonic boom that occurs during sonic flight and also the condensed water(?) coner(?) that appears behind the plane.
I've tried looking it up but I couldn't find any good explanations...
 
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  • #2
ponjavic said:
Could someone try to explain to me the reason for the sonic boom that occurs during sonic flight and also the condensed water(?) coner(?) that appears behind the plane.
I've tried looking it up but I couldn't find any good explanations...

What do you know about Gas Dynamics? Have you ever heard about a Shock Wave, or do you know what's the Mach Number?

I'm only trying to get information to not saying things that seem strange or unknown to you.

Go here and tell me what do you think: https://www.physicsforums.com/showthread.php?t=45265
 
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  • #3
ponjavic said:
Could someone try to explain to me the reason for the sonic boom that occurs during sonic flight and also the condensed water(?) coner(?) that appears behind the plane.
I've tried looking it up but I couldn't find any good explanations...

When an aircraft flies through the sky, sound waves bouce off of the plane. When the plane flies faster than the waves, the plane makes a sonic boom sound as it flies through the sound waves. The water that's condensed on the plane then comes off at the moment of the sonic boom.
 
  • #4
Ok but this is no physical (not the word I'm looking for) explanation it's just an order of events.
When an aircraft flies through the sky, sound waves bouce off of the plane. When the plane flies faster than the waves, the plane makes a sonic boom sound as it flies through the sound waves. The water that's condensed on the plane then comes off at the moment of the sonic boom.
 
  • #5
some answers...
What do you know about Gas Dynamics? Have you ever heard about a Shock Wave, or do you know what's the Mach Number?

I know the gas law, I have taken a peek at bernoulli's equation, I have understood that when flying faster than the speed of sound the density of air is allowed to be changed (is this important).
I know what a shockwave is and 1 mach is speed of sound while 5 mach is 5*speed of sound

The other forum thread you posted unfortunately did not help me. It spoke of some singularity which I couldn't see.
I wonder if the condensation continues to follow the plane or is it just as it breaks the barrier? Because the sonic boom continues after the plane has broken the barrier...
 
  • #6
ponjavic said:
some answers...


I know the gas law, I have taken a peek at bernoulli's equation, I have understood that when flying faster than the speed of sound the density of air is allowed to be changed (is this important).
I know what a shockwave is and 1 mach is speed of sound while 5 mach is 5*speed of sound

The other forum thread you posted unfortunately did not help me. It spoke of some singularity which I couldn't see.
I wonder if the condensation continues to follow the plane or is it just as it breaks the barrier? Because the sonic boom continues after the plane has broken the barrier...

Nevermind, Ponjavic. The sonic boom is the consequence of a shock wave. Once the aircraft has reached the sound speed, the particles of air upstream the nose don't feel the presence of the aircraft structure. Thus all of them collide violently with the aircraft surface. It results on a strong increasing of pressure and temperature in the nearbies of the aircraft nose wall. The main property of such a shock wave is that suddenly increasing. In fact it is a discontinuity inside the flow field. That discontinuity is propagated across the flow field and the shock is convected along in an arrow shaped form just in front of the nose (have you ever seen that shape?). When you're on the street and hear the sonic boom, your ears are felling that jump of pressure produced by the shock extremes.

As the condensed water is concerned, I'm trying to clear it up to myself. But it is not an easy problem, because of that singularity you mentioned. I haven't understood that so far. The singularity of Prandtl-Gaulert is a singular effect of such flows into air. In fact, the condensation remains always if the pressure is small enough to condensate the vapor. The problem is behind the shock the pressure is increased, so that it would be hoped not to have any condensed vapor behind the shock.
 
  • #7
Ok that gave me a little more insight, thank you =)
 
  • #8
Air, like any gas can be compressed into a liquid, the action of the airfoil or wing compresses the air and forms the liquid water vapor. Condensation.

The sonic boom is the loud noise created when a high pressure wave followed by a low pressure wave of an aircraft traveling faster than the speed of sound, not just overcoming the sound barrier.

The sound of piled up compression waves converging at your ear.
 

1. How are sonic booms and condensation trails related?

Sonic booms and condensation trails, also known as contrails, are both caused by airplanes traveling through the air at high speeds. The sonic boom is created when an aircraft reaches or surpasses the speed of sound, causing a sudden increase in air pressure. This pressure wave can create a loud noise heard on the ground. Condensation trails, on the other hand, form when hot exhaust from an airplane mixes with the cold air in the atmosphere, causing water vapor to condense and form visible trails.

2. Why do sonic booms occur?

Sonic booms occur when an object travels faster than the speed of sound, which is approximately 767 mph at sea level. As the object moves through the air, it creates pressure waves that combine and form a shock wave. When this shock wave reaches the ground, it can be heard as a loud noise, known as a sonic boom.

3. Are sonic booms dangerous?

Sonic booms themselves are not dangerous, but they can be startling and disruptive to those on the ground. They can also cause damage to buildings and other structures if they are strong enough. However, modern aircraft are designed to minimize the impact of sonic booms and regulations are in place to restrict supersonic flights over populated areas.

4. How do condensation trails form?

Condensation trails form when hot water vapor from an airplane's exhaust mixes with the cold air in the atmosphere. The water vapor then quickly condenses and freezes into tiny ice crystals, forming a visible trail behind the airplane. The length and persistence of the trail depend on factors such as temperature, humidity, and wind speed.

5. Do condensation trails contribute to climate change?

There is ongoing research on the potential impact of condensation trails on climate change. Some studies suggest that these trails can trap heat in the atmosphere, contributing to the warming of the planet. However, the overall impact of contrails on climate change is still being studied and is considered to be a minor factor compared to other human activities that contribute to climate change.

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