WHAT THE HECK IS GOING ON HERE?

Answer:

There are two(2) things going on!!

!) Bob only typed two sentences on this posting!!

That is all I have!! :-)

Les

Answer:

There are two(2) things going on!!

!) Bob only typed two sentences on this posting!!

That is all I have!! :-)

Les

--------------------------------

Cameras don't have binocular (stereoscopic) depth perception, the two streams may pass without touching. Lack of depth perception is the reason the movie / TV stunt of punching someone in the jaw works, the victim reacts when the fist passes in front of them.

Close one eye and try touching things from the side with a finger. Your one open eye gives you an answer that may be wrong.

Its not a trick. At least not that kind of trick. There are in fact two laminar streams impacting and deflecting from each other. Two cues in the video support this. (1) There is a visible interface line between the streams. (2) Periodically a perturbation or disturbance of some kind cause the two stream to converge for a fraction of a second. It is what it looks like. Two laminar flowing streams making contact and deflecting from each other.

I suppose I could have recorded a longer video (drained about 2 gallons this way), but I thought everything necessary to at least know what is happening if not the cause was available in the 9 second video, and making a longer video would have seemed like useless auto flagellation.

This fluid started out as a mix of distilled water and about 5% SC520 cutting fluid. The tank has not been cleaned in a couple years. I know. My bad. #2 way oil has been oozing out of the machine every 15 minutes when the automatic oil is activated to lubricate the cast iron ways and ball screws. I suspect it is more way oil than water, but I have kept the tank topped off with water and cutting fluid. I haven't worried to much about it since I have ONLY use this particular machine for engraving for the last several years.

Jim, I am disappointed. In spite of your tendency to start off with a new topic at some point temporally displaced from the tangent point in some of your unrelated replies to topics, I figured this one would be right up your 7-10 split.

One person (in a forum) said with authoritarian demeanor that, "This is a non Newtonian fluid." I neither agree nor disagree. I just don't know. It was an interesting anomalous visible occurrence I found interesting enough to waste 9 seconds recording video, and an indeterminate number of additional seconds sharing the video with others.

While it was happening I cut 3 molds that will be shipping to Hawaii. The day before I spent most of the afternoon cleaning out two machines and adding a coolant tap for a wash down hose. I'll finish cleaning out this machine, and add a tap for a coolant hose to it today and tomorrow. I'm also going to do an experiment with a dual tank design, that should isolate fines and floating oil to the first tank. If I like how it works I may change all/most of my machines to a dual tank design.

Now I am off to 3D model some fish hooks. Yeah really.

If I have time later today I'll make a one piece bulkhead connector for joining the two tanks. Well, one piece body. It will still have two nuts and two gaskets as well. Well either that or go fishing.

I wonder if its possible the two streams are just flowing through each other? The visible cues would be the same.

Nah, not a chance. They would converge.

Inertia of the fluids may be more important here than deflection effects. See some of the discussion at

The reddit page alludes to non-Newtonian fluids; with concensus seeming to be that non-Newtonian effects in milk-pouring are trivial enough to be ignored. If the coolant and milk have similar flow rates, viscosity, density, and surface tension, such effects probably can be ignored here too. (See Reynolds and Froude numbers.)

Seems to be more complex than that; else the streams wouldn't cross twice, as they visibly do at about 2 seconds in. Obviously some Coanda effect going on. Note, for Rayleigh jet instability effects see "On the collision of laminar jets: fluid chains and fishbones", 2004, by John M. Bush and Alexander E. Hasha.* The Bush / Hasha experimental setup shown in Figure

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Inertia of the fluids may be more important here than deflection effects. See some of the discussion at

The reddit page alludes to non-Newtonian fluids; with concensus seeming to be that non-Newtonian effects in milk-pouring are trivial enough to be ignored. If the coolant and milk have similar flow rates, viscosity, density, and surface tension, such effects probably can be ignored here too. (See Reynolds and Froude numbers.)

Seems to be more complex than that; else the streams wouldn't cross twice, as they visibly do at about 2 seconds in. Obviously some Coanda effect going on. Note, for Rayleigh jet instability effects see "On the collision of laminar jets: fluid chains and fishbones", 2004, by John M. Bush and Alexander E. Hasha.* The Bush / Hasha experimental setup shown in Figure

• formatting link