Third Generation Hall Effect Firing

The team conducted our 57th MHD generator firing test Saturday. This was our third generation Hall Effect core. This was also our first time using two plasma sources (rocket motors).

View from the exhaust side The front side

Down the throat Dual Firing Harness


Motor Start Ejection charges

Motor start and finish. The motors we use to create the plasma are made for small rockets. They have a reverse charge at the end intended to deploy a parachute.

The good news is that everything worked, the bad news is that the performance was poor. We have four more firing test planned for this unit. On each of the next tests a difference single parameter is adjusted. This should start pushing the performance up.

5 Responses to “Third Generation Hall Effect Firing”

  1. Yosh Shimono says:

    Having watched these tests of the MHD and all the problems you have with the porcelain linings, I was wondering how you prevent the 2000+degree heat from destroying the Neodymium magnets? Is the insulative quality of porcelain great enough to keep them cool? I heard that Neodymium magnets start losing flux once the temperature reaches between 700 and 800 degrees. Just asking.

  2. Cole Santos says:

    This is a real inspiration to see your ambition. I would suggest building your own motors so that you can seed the plasma with potassium ions. This will increase output beyond black powder estes engines.

  3. Administrator says:

    We’re getting away with the heating due to the very short run times. Later we’ll need to actively cool the magnets.

    At this stage the tests are comparative. The total power doesn’t matter as much as being able to compare one firing to the next. It lets us see the effectiveness of the changes in the design. The estes motors are very consistence and are ideal for the moment. Once the MHD unit starts running on the quad engine we’ll start to see some real power output.

  4. Jef Menager says:

    I wonder if the “over-and-under” arrangement of the plasma sources might have some impact on the MHD output. It seems that, since both motors are putting out what are basically conical section plumes, there would be a significant “overlap” area where the the two plumes cross.

    Would that cause a significant change in the flow characteristics of the resulting plume? would it effect the performance/output of the generator?

    Is the admonition “Don’t cross the Streams!” at work here?

  5. Aanta says:

    I were a bit surprised seeing the fireworks there. And then I thought struck. Are you doing these tests in a normal atmosphere with oxygen present?
    I understand that building a good vacuum chamber is beyond your budget. But a closed space filled with nitrogen should not be that costly, it would not even have to be fancy, and I do think the outcome would be somewhat different.