The Stefan Marinov Motor (siberian coliu) and why he was wrong

[broli]

I finally came around to performing an experiment to demonstrate the effect Stefan Marinov saw in his Siberian Coliu. However the only mention of that the location of the brushes might dictate the direction of rotation came from TinselKoala and the Warlock wheel. So I explored this scenario in the below video:


https://www.youtube.com/watch?v=frHOpzMDqSg


And indeed the direction of rotation is dictated by where the wire enters the liquid and this can be explained as well using the Lorentz force. So Marinov was wrong in his conclusion that the direction of the current around the magnet caused the rotation. He could have seen this himself if he did not limit the experiment to current coming from the outer edges.
However this experiment leaves further food for thought and I also wanted to publish into the public domain as I was looking tirelessly for a similar experiment online to no avail, so hopefully it will aid others in their quest without having to waste too much time on these questions and perhaps form new ideas and experiments based on it.

[broli]

Nicely done indeed. I never thought of using a conductive liquid for the entire  "stator ring". You have demonstrated what I've tried to explain many times over, that the direction of rotation of the stator ring depends on whether you inject current on the inner or outer edge. You have left out something very important though: the direction the magnet armature wants to turn. If you can, try to make an experimental setup that allows the armature to rotate as well. You will find, then, the very most interesting thing about the Siberian Coliu, in my opinion. I think it will work with your liquid stator, as it did for me with the solid copper ring stator. Depends on the amps of current in the ring, needs to be enough to generate a reciprocal field for the armature leakage flux to interact with. Try it!

Hi TK, I think I'll just answer your question here. I understand very well what you are getting at. However you must consider all aspects and dynamics of the system to predict the movements. For instance using a liquid, one can see a new previously unknown dynamic happening at the top and bottom of the magnets near the pole splits. This is especially evident at 2:55 in the video, where you see rotation in the liquid at the top and bottom while the electrodes are in the "balanced" position.
This interaction should also influence the rotation of the magnet. And this also begs the question what would happen if the magnet was a strong electromagnet which consists of a ring and a bar going across it. Would the ring of this magnet move while the bar remain stationary, if so where would the back emf reside in such ring which has no transverse component. When you realise this is pretty much the same as a homopolar motor with the added freedom of reversing the poles many interesting questions arise.

[TinselKoala]

No, you are missing it.

First, let's please try to use common terminology so as not to become confused. The RING is referred to as the "stator" and the magnet armature is the "rotor" or simply armature.

Now, in order to see the full range of phenomena that this system can produce, one must explore several interactions.
1. what happens when the ROTOR is fixed and cannot move and the ring STATOR is fed with current at diametrically opposed points: both on inside radius, both on outside radius, both opposite "split" in rotor, both 90 degrees to split, etc. You have demonstrated part of this behaviour, showing how the ring stator wants to move in various conditions.
2. what happens when the ROTOR is allowed to turn on its axis and the ring STATOR is fixed and cannot move, and the stator is fed with current at the same points as above. Now you will determine what the ROTOR wants to do in various conditions.
3. Most important: test when both ring STATOR and magnet ROTOR or armature are free to rotate. Repeat feed point and orientation tests above. You are looking for how the stator and rotor interact when both are free to move, from various starting orientations.  Repeat ring current injection tests as above. It is this third series of tests which, if properly performed (and if your liquid stator ring behaves like the solid ring) will blow your mind.

As I said before I don't know if the liquid stator will be able to show all the relevant results. You may want to get hold of some copper vacuum gaskets and make a slightly more complicated test apparatus.

[broli]

No, you are missing it.

First, let's please try to use common terminology so as not to become confused. The RING is referred to as the "stator" and the magnet armature is the "rotor" or simply armature.

Now, in order to see the full range of phenomena that this system can produce, one must explore several interactions.
1. what happens when the ROTOR is fixed and cannot move and the ring STATOR is fed with current at diametrically opposed points: both on inside radius, both on outside radius, both opposite "split" in rotor, both 90 degrees to split, etc. You have demonstrated part of this behaviour, showing how the ring stator wants to move in various conditions.
2. what happens when the ROTOR is allowed to turn on its axis and the ring STATOR is fixed and cannot move, and the stator is fed with current at the same points as above. Now you will determine what the ROTOR wants to do in various conditions.
3. Most important: test when both ring STATOR and magnet ROTOR or armature are free to rotate. Repeat feed point and orientation tests above. You are looking for how the stator and rotor interact when both are free to move, from various starting orientations.  Repeat ring current injection tests as above. It is this third series of tests which, if properly performed (and if your liquid stator ring behaves like the solid ring) will blow your mind.

As I said before I don't know if the liquid stator will be able to show all the relevant results. You may want to get hold of some copper vacuum gaskets and make a slightly more complicated test apparatus.

Yes I know. There are cases where in the tests you describe there seems to be a violation of Newton's third law where the magnet and ring rotate in the same direction. HOWEVER this is merely an illusion when you do not account for all forces/interactions. One important factor is the "outside" electrodes, when you have them close to the magnet these interact with it as well. Even Though the ring would then be spinning in the same direction as the magnet, these electrodes are really the main cause of the magnet spinning in the first place and if also accounted for they would spin in the opposite direction. I did these tests a while ago off camera with solid conductors.
Ad far as I know newton's third law is unbreakable in this setup, otherwise you could simply strap everything together and apply current and see it spin to terminal speeds. that to me is the ultimate test that all forces cancel out.


However my main conclusion from this was not that there would be some strange results in the rotation of the setup. Infact I already KNEW the ring's rotation direction is dependent on where the current enters it. It would not even spin if its radial thickness got smaller and smaller as to leave no radial component for the entering current to move in, which is as you can see in the video the main reason the liquid spins, and why it's balanced when the electrodes are put in the middle of the ring.
My main quest and goal though is not mentioned here yet, and that has to do with the generated EMF's in this setup which little to no one has explored before.

[jimbo]

Sorry to be off topic I don't see any other way to do this .does anyone know were I can access... My out box at ?.no clue ! I've looked a lot but nothing .again sorry .jim