## Virtual Polywell

Discuss how polywell fusion works; share theoretical questions and answers.

Moderators: tonybarry, MSimon

tombo
Posts: 334
Joined: Fri May 09, 2008 1:10 am
Location: Washington USA
Just because it is not intuitive does not mean I don't want to learn it.
Open source is good. Standard is good.
I'm running an older XP machine. Would linux be better for blender?
How much of the octahedron is modeled in the cube of arrows?
I can't find the conductors.
All the arrows are pink not red and blue.
Yes I think a finer grid of arrows would help see what is going on.
The parts I really want to see (besides the overall configuration) are the centers of the triangles where the cusps are.
I expect them to be halfway between those of circular coils and of corners.

I just gave my girl her first driving lesson today, clutch and all.
I feel kind of like she did trying to fly through blender.
It might be a couple of days before I can get back to this, duty calls.
-Tom Boydston-
"If we knew what we were doing, it wouldn’t be called research, would it?" ~Albert Einstein

drmike
Posts: 825
Joined: Sat Jul 14, 2007 11:54 pm
Contact:
tonybarry wrote:Hello Dr. Mike,
Thank you for the sim results. I have Blender running OK on my Mac and I can visualise the field vectors. I am still learning Blender, so I have yet to work out sections ...

Would it be possible to you to publish two sections through your dataset? Both along the polar axis. One running through an equatorial coil centre, and one running through the point where two equatorial coils touch.

For the sake of further conversation, we might call these two planes Meridian Zero (through the equatorial coil centre) and Meridian 45 (through the equatorial coil touchpoint).

The plots along each of these planes would be:-

*B Field (magnetic) ... X and Y as distance from the polar axis, transparent to red colour as field strength. This is a 2D plot. Overlaid on this is
an arrow display indicating the B field vector on a given grid throughout the section. The section is viewed at an isometric angle (i.e. about 30 - 45 degrees to the plane). The arrowlengths are proportional to field strength.

*E Field (electric) ... X and Y as distance from the polar axis, blue colour as electron density, red colour as ion density (if these are determined individually) or red to blue colour as E field strength if not.

Total 4 images.

Regards,
Tony Barry
Yeah, I think so. That's what the "render" operation is supposed to do, but I haven't quite figured out how to save an image yet. I did figure out I can use the "view navigate" commands to "fly" around the data.

The colors didn't quite come out the way I wanted, but I can easily play with that. Separating the data sets is also pretty easy, I just have to save the data to different files.

The arrows change length for "weak" values, and change color for "strong" values. It's a linear mapping though. Even "flying" thru all the arrows gets mighty confusing, so I'll see what I can do.

drmike
Posts: 825
Joined: Sat Jul 14, 2007 11:54 pm
Contact:
tombo wrote:Just because it is not intuitive does not mean I don't want to learn it.
Open source is good. Standard is good.
I'm running an older XP machine. Would linux be better for blender?
It works on my machine, I would think that because they have a huge
army of programmers it should work on XP just as well. I need to fix
my xp partition so I can use the tools that came with a low cost dsp I
just got....
How much of the octahedron is modeled in the cube of arrows?
I can't find the conductors.
I didn't draw in the conductors. If you can figure out how to do that it'd
be great! There is only one section of a conductor which is a 45 degree
segment around the x axis. It's actually just a line in the calculations, so
it has no thickness.
All the arrows are pink not red and blue.
Yes I think a finer grid of arrows would help see what is going on.
The parts I really want to see (besides the overall configuration) are the centers of the triangles where the cusps are.
I expect them to be halfway between those of circular coils and of corners.
Yeah, I didn't make copies of the data. That would make those parts stick out better.
I just gave my girl her first driving lesson today, clutch and all.
I feel kind of like she did trying to fly through blender.
It might be a couple of days before I can get back to this, duty calls.
I'm a year out on that yet. Good luck!

Solo
Posts: 261
Joined: Fri Jun 29, 2007 12:12 pm
Location: Wisconsin
Here's a link to the abstract of an article on computational investigation of the Polywell system! I haven't got access to the article myself, but does anyone else subscribe to that source?

Edit: sorry, I forgot the link I guess . Here's one, not the same, but interesting none the less.
Last edited by Solo on Sat Jul 19, 2008 1:49 am, edited 1 time in total.

scareduck
Posts: 552
Joined: Wed Oct 17, 2007 5:03 am
Solo wrote:Here's a link to the abstract of an article on computational investigation of the Polywell system! I haven't got access to the article myself, but does anyone else subscribe to that source?
Uh ... where?

tombo
Posts: 334
Joined: Fri May 09, 2008 1:10 am
Location: Washington USA
OK Dr Mike I give up, where did you hide the wires?
Specifically, what are the coordinates of the ends of the conductor segments in the blender model?

I finally got blender to run.
It is a lot more intuitive now that it actually works.
It only works for me in my Linux partition (Unbuntu 7.10) with my son's mouse.
Unfortunately my Linux does not run my wireless internet card so I have to go up into the attic to plug in physically.
OK, enough whining.

I can sort of see where the conductors must be sometimes.
How did you get it to show red & blue arrows? Rendering? Not on mine.
I think I can see how to draw the turns if I can tell where to put them.
Looking up close, your arrows are cute.
-Tom Boydston-
"If we knew what we were doing, it wouldn’t be called research, would it?" ~Albert Einstein

drmike
Posts: 825
Joined: Sat Jul 14, 2007 11:54 pm
Contact:
You have to play with the lamp to get the lighting to work. I usually move the data then unselect it to get rid of the edging. It makes the colors come out. But only if you have the lamp on the "outside" of the arrows. I haven't figured out which side is the outside - I don't quite understand the shading algorithm. It must pick it when I create the data though.

The wires do not exist in the arrow file. But if you roll the data around, you can see arrows going in circles. The center of those circles is where the wire is.

The idea behind the shape of the arrows is that they are simple so the 3D tool can move them fast and look like arrows from almost every direction. I'm glad they are properly suggestive!

But I agree it's kind of a pain to see any color. When I have the lamp in the wrong place, everything is just dark.

My son gave up on 3Dmax. I think you have to love it a lot to make things look good. For me, it's more like "OK, I think I get it now. Time to build some hardware and make a lot of noise!"

drmike
Posts: 825
Joined: Sat Jul 14, 2007 11:54 pm
Contact:
A little over a year ago Tombo asked about a straight wire configuration, and I posted some math that figured out the field for it. I had the opportunity to actually use that in my day job, and what I found was that my starting point was slightly wrong, so that while I got the units right, I had done the wrong integral. Since I actually needed the straight wire fields for a real problem, I fixed it. The corrected paper is posted on my web page (which still is a really bad (and that's an understatement!)): tombo.pdf

tombo
Posts: 334
Joined: Fri May 09, 2008 1:10 am
Location: Washington USA
Kiteman created an Excel spreadsheet to do a similar job for an arbitrary set of conductors using a numerical integration of the of the Biot-Savart equation.

It was posted here In the thread "Is There an Optimal Size for Magrid Casings?":
I'm sorry, slipped my mind. Here it is. http://taenia.homestead.com/files/MagCalc2.xls
What do you think of his implementation?
I have been using it to model some magrid configurations for him.
I use it to generate autocad script files to 1. draw the coils 2. show field vectors in any slice or volume desired.
I plan to apply it to my configurations soon.

I hope you've been having fun blowing things up.
-Tom Boydston-
"If we knew what we were doing, it wouldn’t be called research, would it?" ~Albert Einstein

drmike
Posts: 825
Joined: Sat Jul 14, 2007 11:54 pm
Contact:
I'll have to get that from work - at home I don't have xcell.

If it's direct numerical integration, should be fine.

The problem with blowing things up is that it takes time to replace the parts.

I mostly have to deal with life this summer, so it will be a long time before I can really have some fun. But I do look at the pile of parts every few days, and the next step really is plugging things in and watching for smoke. If it works, I'll be a lot closer to my welder/magnet control circuit then I was last year!

Rick Brice
Posts: 12
Joined: Fri Aug 29, 2008 9:06 pm
Location: Atlanta, GA
Contact:

### Coriolis Effect

A thought on this virtual model came to me this AM. In all this discussion, I have not heard Coriolis Effect discussed. I believe that this effect cannot be ignored in this model or the real world machine.
RH Rule? But I'm Left-handed!

Art Carlson
Posts: 794
Joined: Tue Jun 24, 2008 7:56 am
Location: Munich, Germany

### Re: Coriolis Effect

Rick Brice wrote:A thought on this virtual model came to me this AM. In all this discussion, I have not heard Coriolis Effect discussed. I believe that this effect cannot be ignored in this model or the real world machine.
Why in heaven's name would you want to calculate forces in a rotating reference frame?

Rick Brice
Posts: 12
Joined: Fri Aug 29, 2008 9:06 pm
Location: Atlanta, GA
Contact:
We are in a rotating reference frame.

I believe that the rotation of the earth will impart an angular momentum to the plasma that we cannot ignore.

Think of the rotation of the water in a flush toilet. It is just that simple.

I've read nearly everything on this forum in Theory and Design.
Reading the discussions on the need for the model to be dynamic brought to mind the impact of Coriolis on the accuracy of Inertial Navigation Platforms.

I do believe that the Coriolis Effect will impart spin on the plasma.
RH Rule? But I'm Left-handed!

Art Carlson
Posts: 794
Joined: Tue Jun 24, 2008 7:56 am
Location: Munich, Germany
Rick Brice wrote:Think of the rotation of the water in a flush toilet. It is just that simple.
That says everything.

chrismb
Posts: 3161
Joined: Sat Dec 13, 2008 6:00 pm

### Re: Coriolis Effect

Art Carlson wrote: Why in heaven's name would you want to calculate forces in a rotating reference frame?
Outright circumferential instabilities and small imbalances will likely send the plasma tumbling. Seems quite plausible to me. Not sure whether it'd be micro, unit or mega rad/s, but there doesn't seem to me to be anything to stop rotation of the reactants - apart from the fabled 'annealing', perhaps; the 'fix-all' solution to Polywell's thermalisation problems and general nuisance ions that do what they like.

Maybe there could be processes that create self-balancing populations of particles in counter-rotations - there again, maybe not? - but we're agreed that pure radial motion isn't a given
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