Titan implosion: underwater shockwave?

Click For Summary

Discussion Overview

The discussion revolves around the implications and effects of the Titan submersible's implosion, focusing on the potential for shock waves, energy release, and impacts on marine life. Participants explore various theoretical aspects, including the temperature changes within the vessel, the nature of shock waves generated, and hypothetical scenarios regarding visibility in the water following the event.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • Some participants question whether a shock wave was caused by the implosion, suggesting it was inevitable.
  • There is speculation about the potential for marine life to be affected similarly to “fishing with dynamite,” with discussions on the estimated kill radius based on the implosion's characteristics.
  • Participants debate the claim that the interior of the vessel could have reached temperatures comparable to the surface of the sun, with some suggesting a plausible significant temperature increase during the implosion.
  • Calculations are presented estimating the energy released during the implosion, with back-of-the-envelope figures suggesting it could be equivalent to detonating around one hundred kilograms of TNT.
  • Some participants discuss the dynamics of the implosion, including the speed of collapse and the resulting water displacement, proposing that the velocity of displaced water would decrease with distance from the implosion.
  • There are references to the testing of a scale model of the Titan and its implications for understanding the dynamics of the actual implosion.

Areas of Agreement / Disagreement

Participants express differing views on several aspects, including the nature of the shock wave, the temperature changes within the vessel, and the effects on marine life. The discussion remains unresolved with multiple competing hypotheses and calculations presented.

Contextual Notes

Some calculations depend on assumptions regarding the volume of the Titan and the pressure conditions at the ocean floor. The discussion includes limitations related to the non-ideality of gases under high pressure and the complexities of underwater acoustics.

Lieutenant Barclay
Like many I’ve been captivated by the Titan story. I’m wondering a few things:

1. Was a shock wave cause by the implosion?
2. Would marine life have been killed similarly to “fishing w/ dynamite”? Kill radius?
3. A TV talking head claimed the inside of the vessel would have heated to “a temp the surface of the sun” for a fraction of a second - true or BS?
4. How much energy was released when it imploded?
5. I read Rush tested a 1/3 scale model in a chamber at U Washington. Supposedly the test implosion shook the building and blew out the sensors. Can anyone link to a picture of the kind of chamber used for these tests?

Finally, timing indicates the implosion did not take place on sea floor but rather hundreds of meters above. If it HAD happened on the sea floor, would it have caused an “underwater sandstorm” i.e. temporarily block visibility from kicking up so much sand? How long would the sand have taken to settle?

RIP to the 5 souls lost.
 
Physics news on Phys.org
Lieutenant Barclay said:
How much energy was released when it imploded?
That will be the product of the pressure and the volume imploded.
In back-of-the-envelope numbers…. Say that the volume of the Titan was about ten cubic meters, pressure at the ocean bottom 400 atmospheres or ##4\times 10^7## Pascal, the explosive TNT releases about 4000 Joules per gram, we’re talking roughly the equivalent of detonating one hundred kilograms of TNT.
Lieutenant Barclay said:
A TV talking head claimed the inside of the vessel would have heated to “a temp the surface of the sun” for a fraction of a second - true or BS?
The surface of the sun isn’t that hot, about 6000 degrees Kelvin. Figure the interior of the submersible was at about 300 K…. With no time to dissipate heat a twenty-fold temperature increase during the energy release is quite plausible.
 
Reply
  • Like
Likes   Reactions: Klystron, russ_watters and Borg
Nugatory said:
That will be the product of the pressure and the volume imploded.
In back-of-the-envelope numbers…. Say that the volume of the Titan was about ten cubic meters, pressure at the ocean bottom 400 atmospheres or ##4\times 10^7## Pascal, the explosive TNT releases about 4000 Joules per gram, we’re talking roughly the equivalent of detonating one hundred kilograms of TNT.

The surface of the sun isn’t that hot, about 6000 degrees Kelvin. Figure the interior of the submersible was at about 300 K…. With no time to dissipate heat a twenty-fold temperature increase during the energy release is quite plausible.
Not by my back of the envelope calculations.
The contents of the submarine were air. Not helium or other inert (monoatomic) gases. That leaves adiabatic exponent 1,4.
Which means that compressing air to 1/32 (1/25) initial volume should raise its temperature 4 (22) times and pressure 128 (27) times.
The pressure will have been limited by the sea pressure (under 400 bar). And the other thing limiting heating is nonideality of compressed gases. Thew compressibility of gases drops off drastically above 100 bar as their density and properties approach liquid ones. Gases above 200 bar are little compressed by further pressure - and little heated.
Say it reaches 5x original temperature... that would be just 1200 Celsius?
 
Lieutenant Barclay said:
1. Was a shock wave cause by the implosion?
It had to.
Lieutenant Barclay said:
2. Would marine life have been killed similarly to “fishing w/ dynamite”? Kill radius?
Let's imagine the sub is a sphere of about 2.25 meters. (The actual volume of the Titan was 47 m³.)

Let's imagine the speed at which the sub collapses is at the speed of sound (in air). The initial speed would have been 1200 km/h and, as the temperature increases 5 times (per @snorkack 's post), it would have reached 2700 km/h by the end of the process. Let's assume an average velocity of 2000 km/h.

The velocity of the water displaced will drop around the sub as the distance increases per the sphere area ratio, i.e. the radiuses ratio squared. Compared to our initial radius of 2.25 m, at a 22.5 m distance, the velocity would drop to 2000*(2.25/22.5)² = 20 km/h. This would begin to feel like a light breeze to anyone at this distance from the sub. At 10 m, you would feel a 100 km/h water wave rushing through you, which must be pretty wild.
 
Reply
  • Informative
Likes   Reactions: pinball1970
jack action said:
It had to.

Let's imagine the sub is a sphere of about 2.25 meters. (The actual volume of the Titan was 47 m³.)

Let's imagine the speed at which the sub collapses is at the speed of sound (in air). The initial speed would have been 1200 km/h and, as the temperature increases 5 times (per @snorkack 's post), it would have reached 2700 km/h by the end of the process. Let's assume an average velocity of 2000 km/h.

The velocity of the water displaced will drop around the sub as the distance increases per the sphere area ratio, i.e. the radiuses ratio squared. Compared to our initial radius of 2.25 m, at a 22.5 m distance, the velocity would drop to 2000*(2.25/22.5)² = 20 km/h. This would begin to feel like a light breeze to anyone at this distance from the sub. At 10 m, you would feel a 100 km/h water wave rushing through you, which must be pretty wild.
Hi Jack,
Could do with your input on the other Titan thread. It is an engineering/ acoustic question. @russ_watters and @Baluncore and @aorlanda can help?