Weird pulse waves in a tunnel

Abats

Dagobah Resident
FOTCM Member
A contact on facebook just post this youtube video (CAPTURED ON VIDEO: POSSIBLE GLITCH IN OUR MATRIX - Antioquia, Colombia 2018) and I unable to say if it's a edited footage or not. It's quite interesting and weird. In the description we can read this :
I have personally confirmed and verified this is original video footage of what appears to be some sort gravitational anomaly and or disruption in underground electromagnetic anomaly that was believed by NASA to be some sort geological threat.? Yeah right! Why do I say threat? Because shortly after the video went public, a clandestine team of scientists and other unknown persons from the US traveled to this tunnel and it was sealed with an unannounced amount of explosives under the cover of darkness. Local village residents who live along the river and near the damn witnessed several teams of unknown people entering the tunnel, then the next day, when there was no work being conducted inside the tunnel and workers were told to not go to the site. There was a massive unexplained explosion, which flooded the entire nearby village. Every resident received an undisclosed settle amount for loss of property and relocation expenses.


What do you think of this ?
 

Under this video showing the same footage, a man said :

This tunnel is running through a dam. The mechanisms inside that are responsible for controlling the flow of water through the dam are periodically causing large pressure fluctuations within the tunnel. When the pressure inside of the tunnel drops, the dew point also drops which causes the moisture in the air of the tunnel to condense and form clouds. The reason the clouds appear only in certain places is because the pressure waves cause interference patterns in the tunnel. The clouds are appearing where there is destructive interference causing low pressure.

And

There is one or more smaller tunnels which are used to control level of water in the reservoir behind of dam. They using that dam also as hydroelectric plant, I guess some of those tunnels are pretty long and more narrow, so they may build some vent shafts to balance internal pressures within of the structure while they open the valves. Those vents must have endings in that big tunnel where is video made, it would definitely cause change of pressure. But also water flow through those tunnels can make ultrasonic waves, they also can cause change of pressure. Pressure variation due to wave interaction is causing the dew point to fluctuate around a constant temperature. If you listen carefully you can hear something like

If someone on the forum is an engineer, can he say if that's a good explanation ?

Edit : spelling
 
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That's very strange. There appears to be a sound accompanied with it. Maybe some sort of pulse travelling though the tunnel? I suppose someone will be able to translate what the men in the truck are saying. Looking at the way the mist curves around the ceiling it doesn't appear to be cgi, as far as I can tell.

According to Wikipedia the attempt to divert the river while constructing the dam was a bit of a disaster:
_Ituango Dam - Wikipedia

"Three tunnels were constructed to divert the Cauca River around the construction site. Two were eventually sealed during construction, leaving a third to divert the river. Between 28 April and 7 May 2018, three landslides blocked the tunnel, leading the reservoir to fill. Engineers attempted to open the two closed tunnels with explosives but were unsuccessful. On 10 May, when the reservoir reached the power station intake, engineers began releasing water through the unfinished power house to prevent a breach of the dam. On 12 May one of the previous sealed tunnels naturally reopened, which suddenly increased downstream flows by three times the average. This promoted evacuations downstream, eventually totaling around 25,000.

On May 16 silt build-up in a portion of the power house, the only means to drain the reservoir, led to water escaping into a transit gallery used by construction vehicles. The water eventually poured onto the downstream face of the dam, eroding the roadway and a portion of the riprap. Subsequently, EPM announced a risk of collapse existed and workers continued to fill the dam to its design height in hopes the spillway could be used to prevent an over-topping of the dam. Heavy rainfall was expected in the Cauca River basin through the end of May.

On May 19 the dam works reached level 405 masl; 5 m below cofferdam target the level. On May 25 Dr Ordoñez issued a letter expressing his panic about the situation because "Ituango project is dead and there is no control over it, so the most natural thing is to expect it to fail; we are sure that it is easier to fail than not to fail, and we are truly in a panic"."
 
That's very strange. There appears to be a sound accompanied with it. Maybe some sort of pulse travelling though the tunnel? I suppose someone will be able to translate what the men in the truck are saying. Looking at the way the mist curves around the ceiling it doesn't appear to be cgi, as far as I can tell.

Because of the accent and pronunciation I'm not entirely sure, but I think they are saying something like:

- See how it's hitting the car hard.
- Yeah.
...
- ...The whole tunnel is like that.
- Yes, the b*tch (?) is trying to find the exit any way it can.

It does sound like a natural conversation, which adds to the credibility. The way the lights of the car hit the mist when it appears also make it look real. :shock: If someone did CGI this they made a brilliant job! Pretty cool, and kind of scary. I'm not sure I'd dare to drive through that! :lol:
 
What I find impressive is that there's no water on the car going through the fog. Assuming that 1) it's water 2) it seems to come up from the ground. I mean, the car goes through like this without turning on its wipers, it's very strange or I'm just ignorant about this phenomenon ^^
 
What I find impressive is that there's no water on the car going through the fog. Assuming that 1) it's water 2) it seems to come up from the ground. I mean, the car goes through like this without turning on its wipers, it's very strange or I'm just ignorant about this phenomenon ^^

Usually for fogs just the headlights are enough. It would depend on the size of the water droplets I suppose.
 
Originally I thought it was CGI, but I changed my mind. Although the movement does look unnatural I think now it's natural, based on this video:


Google translated description reads:
Ituango Hydroelectric Project - Cavitation Phenomenon in Access Tunnels to the Machine House.

Dear colleague,
We invite you to follow us on our social networks:

FACEBOOK: https://www.facebook.com/AICTES

In this space we will be able to interact and find updated information on Academic Events, as well as outstanding News related to civil engineering and underground space.

Google translated comment under the video reads:
Although Cavitation is a natural phenomenon, it is not very welcome in hydraulic projects or works. Esw synonymous with unwanted vibrations and turbulence

ESW = Extracorporeal shockwaves?? It's the only acronym I can find related to cavitation, but it may be a translation issue.

I haven't checked, but I think this dam collapsed a year later - so this may be related?
 
Definitely looks legit. I agree with the guy you quoted from YT @Abats
To me it looks like water vapour and it seems to be appearing and disappearing in sync with some kind of standing wave. What that guy says is that air pressure is the culprit, and it makes perfect sense, but what puzzles me is what could cause the air pressure to change so rapidly (and I would imagine the amplitude would have to be huge) to create and dissolve water vapour so quickly.
 
here is another example occurring with airplanes:
Low Pressure Condensation

Indeed but speed of the plane is involved to produced that so in the tunnel this is some kind of other mecanism ? and how about the sound we heard in the video ? yeah a lot of questions...
 
Indeed but speed of the plane is involved to produced that so in the tunnel this is some kind of other mecanism ? and how about the sound we heard in the video ? yeah a lot of questions...
The sound seems to come right after the vapour surges. I would say that the sound comes from the rapidly changing pressure. It probably causes a very localized surge of wind. Curiosly, there is no other strange sound.
 

Under this video showing the same footage, a man said :



And



If someone on the forum is an engineer, can he say if that's a good explanation ?

Edit : spelling
Whoa that is weird! Never saw anything like that!
 
Found the original reddit thread the video was posted from, including the top comments for reference.

TL:DR; Likely an opposing (standing) wave of low air pressure, causing low pressure condensation (as mrtn pointed out). This explains the alternating locations of the mist.

fucky_fucky

591 points · 2 years ago · edited 2 years ago

Mechanical engineer here. This is probably caused by pressure variations which are causing the dew point to fluctuate. When the pressure drops, the dew point drops with it, and water vapor condenses out of the air to form the clouds you see. There's probably a slight temperature gradient in the tunnel so that the air near the bottom of the tunnel is slightly cooler than the air at the top, which is in turn slightly cooler than the air in the center of the tunnel, which is why the clouds form from the ground up and from the tunnel's surface inwards. My best guess as to why the pressure gradient varies with location in the tunnel is that winds at the tunnel's exits are creating slow-moving opposing pressure waves within the tunnel, and where the waves interact constructively the pressure increases, and where the waves interact destructively the pressure decreases.
Edit: I misspoke. Constructive interference would be the cause of the pressure variations both above and below the dew point. Imagine the x axis in this gif is the dew point and you'll understand what I mean.
Also, I assumed that both ends of the tunnel were open to the environment, thus necessitating the opposing wave theory, but that may not be the case. If one end of the tunnel is closed, this would be a beautiful example of a classical standing wave. In either case, however, the cause remains fundamentally the same: pressure variation due to wave interaction is causing the dew point to fluctuate around a constant temperature. Really neat stuff.
Finally, this dam is under construction, and it may collapse. Perhaps this phenomenon and the weakness of the dam are related in some way?

Dunyvaig

62 points · 2 years ago· edited 2 years ago

There are two missing parts here. One is that the points of condensation are fixed, and the other is that they are alternating:
Shouldn't the phenomenon be rolling down the tunnel if it was as simple as a slow moving pressure wave?
I think you're right in that it is a pressure wave, but that it is a special case of a standing wave.
Here is what I think is happening: (I might be getting the y-axis here the wrong way)
This explains the fixed points, and the intermediate period where the phenomenon doesn't occur.

Plasma_000

11 points · 2 years ago

Yep, my money is on a standing wave of wind in the tunnel.


fucky_fucky

5 points · 2 years ago

You're right. A standing wave is what I was intending to describe, I just didn't name it explicitly. Specifically, I was referring to an opposing wave.

260px-Transient_to_standing_wave.gif
 
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