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Tourist submersible visiting the Titanic is missing Part 2 69

Hi dik. Compare the volume of the Cf at the surface to the volume at implosion pressure. Now compare that change in volume to the internal volume of the hull.
I am not disputing that there may be energy stored in the CF. I am trying to quantify that energy.
Intuitively it seems quite small.
There may well have been heat energy released from the ripping apart of the CF, and from breaking the adhesive bonds to the end rings.
However much heat generated, the North Atlantic is a quite good heat sink. (grin)

--------------------
Ohm's law
Not just a good idea;
It's the LAW!
 
Agreed, waross... I just don't know the relative magnitudes. Even though the volume of the CF was small, I don't know how much energy was stored in it. Like the water compression, this would be given up in a flash (assuming the CF was friable).

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik
 
Dik said:
I'm not so sure... there is a lot of strain energy stored in the compressed CF material of the hull that would be released. I don't know what the magnitude of this is.
Click to expand...

The magnitude is effectively zero compared to the implosive energy associated with the collapse of the void.
 
Thanks...

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik
 
I admire the discussion everyone has provided on the energy released by the implosion and I believe I have followed the logic and calculations on most items except for the expansion of the air volume in the hull after implosion and energy released. If I may indulge everyone's patience:

SwinnyGG said:
If that bubble of air was preserved and allowed to float to the surface, its volume would expand by your 400x multiplier.
Click to expand...

Since the air in the submersible is at ~ one atmosphere, at the instant of implosion, wouldn't it very quickly collapse to 1/400 of its volume at STP, then if it were to rise to the surface it would only expand back to its original 8.3 m^3?

Is it appropriate to equate the implosion force to the gas volume generated by TNT?

Though there is the huge reservoir of potential energy in the full height of the water column, isn't the energy of the implosion only the energy required to cause a failure of the cylinder hoop (assuming the hull cylinder failed) and crumple the material. Thus this would be the intrinsic work potential of the material and not necessarily equivalent to the work required to have the volume created by gas volume? The air in the hull is not pressured, so its pressure is not supporting the water column - the hull structure is doing the function. The hull would hold the water column even if there was a perfect vacuum inside the hull, and if imploded there would be no energy calculation of gas volume equivalent at STP but the sudden inflow of water into the hull void would create the shock wave and water hammer that would tear the structure apart? Where am I going astray???

Thanks - this implosion discussion is very amazing.
 
Run it backwards and see how much Work is required to empty that interior volume at that external pressure. This is what the dynamite comparison example is doing. Whether it is 18 weeks with a hydraulic hand pump or 8 msec with dynamite, the work done is the same. The Power is far different.

If the hull was made of something very rigid and had a vertical cut (the easy way) with a smoothly lubricated surface then the halves could slide and open the interior to the ocean, exposing that void, without any necessary damage to the hull, so it's not a measure of the energy required to cause the hull to fail. Simply having a hatch that opened inwards could allow water in; again, no energy necessarily expended in damage to evaluate the work done.

I believe you are right - the initial air bubble would be reduced 400X by exposure and, as it rose, might regain it's original volume, but it would mostly dissolve into the water and not be a bubble for very long.
 
3DDave said:
Run it backwards and see how much Work is required to empty that interior volume at that external pressure
Click to expand...

Got it! The TNT equivalence is creating filling the void in the water at that incredible ambient pressure. Thanks!!!
 
I've a better understanding of the calculations and descriptions of the energy involved in the implosion. Amazing and staggering!

One more question, and this may have already been explained, sorry if I am retreading: since the communication between the support ship and Titan was via hydrophones, would not the support ship team have already known an implosion had occurred? It would have been heard by their communication system simultaneously to the instant text messaging was lost. The search effort would have been done just because of the hope the sonic blip of the implosion was an unrelated anomaly?,
 
Communication was via acoustic modem. The computer on the support ship was listening for the correctly encoded sounds. Implosion isn't one of those sounds.

If you were at your computer in the good old days of acoustic couplers, the guy at the other end would not hear if your house blew up. All he would know is you stopped typing. Ahh, the days when 300 baud was the upgrade.
 
Thanks 3DDave

Devil is in the details!

I have to smile at remembering the old phone modems: dial up and make sure the phone handset is in the modem cradle!
 
Any water at pressure or altitude above some datum has potential energy. If it moves, its converting PE to kinetic energy and expending some of it. When it flows downhill (under no pressure) at a steady rate, it is expending exactly what it gained from gravity. Energy loss (ft) == decrease in elevation (ft).

--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."
 

I recall the days of the 90 baud acoustic coupler...

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik
 
a real speed demon, as I recall...

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik
 
Something to talk about, the temperature of the implosion.
A diesel engine at idle on a cold day will raise the temperature of the air charge from about 0 degrees C to over 250 degrees c in about 1/2 second, with a compression ratio of 16:1 or less.
What temperature may be reached with a compression ratio of 400:1 ?

--------------------
Ohm's law
Not just a good idea;
It's the LAW!
 
It's a bit academic, isn't it? What's wrong with academic?
Can we look at all aspects of the event?

--------------------
Ohm's law
Not just a good idea;
It's the LAW!
 
Both good questions... I can answer the last one... absolutely nothing is wrong with academic. My grade 7 teacher had a note on his wall, "The only dumb question is the one unanswered."

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik
 
Temperatures as high as 5000°C for a millisecond or two are produced during cavitation, hence it is very damaging (esp to pump suctions), if it is allowed to continue indefinitely. It is just as effective as a continuous acid wash eating away the exposed surfaces quite effectively.

--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."
 
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